Textile seal with air-assisted biasing portion

ABSTRACT

A patient interface comprises a plenum chamber and a seal-forming structure. The seal-forming structure comprises a support structure arranged to support a sealing portion that is adapted to sealing engage the patient&#39;s face in use. The seal-forming structure may also include a seal biasing portion configured to inflate under pressurization within the cavity in the cushion assembly in use to extend the reach of the sealing portion and decouple the sealing portion from external forces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of International Application No.PCT/IB2019/058832, filed Oct. 16, 2019, Australian ProvisionalApplication No. AU2019900644, filed Feb. 28, 2019, and U.S. ProvisionalApplication No. 62/805,147, filed Feb. 13, 2019, each of which is herebyincorporated herein by reference in its entirety.

BACKGROUND OF THE TECHNOLOGY 2.1 Field of the Technology

The present technology relates to one or more of the diagnosis,treatment, prevention and amelioration of respiratory-related disorders.The present technology also relates to medical devices or apparatuses,and their use.

2.2 Description of the Related Art 2.2.1 Human Respiratory System andits Disorders

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower,shorter and more numerous as they penetrate deeper into the lung. Theprime function of the lung is gas exchange, allowing oxygen to move fromthe inhaled air into the venous blood and carbon dioxide to move in theopposite direction. The trachea divides into right and left mainbronchi, which further divide eventually into terminal bronchioles. Thebronchi make up the conducting airways, and do not take part in gasexchange. Further divisions of the airways lead to the respiratorybronchioles, and eventually to the alveoli. The alveolated region of thelung is where the gas exchange takes place, and is referred to as therespiratory zone. See “Respiratory Physiology”, by John B. West,Lippincott Williams & Wilkins, 9th edition published 2012.

A range of respiratory disorders exist. Certain disorders may becharacterised by particular events, e.g. apneas, hypopneas, andhyperpneas.

Examples of respiratory disorders include Obstructive Sleep Apnea (OSA),Cheyne-Stokes Respiration (CSR), respiratory insufficiency, ObesityHyperventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease(COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing(SDB), is characterised by events including occlusion or obstruction ofthe upper air passage during sleep. It results from a combination of anabnormally small upper airway and the normal loss of muscle tone in theregion of the tongue, soft palate and posterior oropharyngeal wallduring sleep. The condition causes the affected patient to stopbreathing for periods typically of 30 to 120 seconds in duration,sometimes 200 to 300 times per night. It often causes excessive daytimesomnolence, and it may cause cardiovascular disease and brain damage.The syndrome is a common disorder, particularly in middle agedoverweight males, although a person affected may have no awareness ofthe problem. See U.S. Pat. No. 4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is another form of sleep disorderedbreathing. CSR is a disorder of a patient's respiratory controller inwhich there are rhythmic alternating periods of waxing and waningventilation known as CSR cycles. CSR is characterised by repetitivede-oxygenation and re-oxygenation of the arterial blood. It is possiblethat CSR is harmful because of the repetitive hypoxia. In some patientsCSR is associated with repetitive arousal from sleep, which causessevere sleep disruption, increased sympathetic activity, and increasedafterload. See U.S. Pat. No. 6,532,959 (Berthon-Jones).

Respiratory failure is an umbrella term for respiratory disorders inwhich the lungs are unable to inspire sufficient oxygen or exhalesufficient CO₂ to meet the patient's needs. Respiratory failure mayencompass some or all of the following disorders.

A patient with respiratory insufficiency (a form of respiratory failure)may experience abnormal shortness of breath on exercise.

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

A range of therapies have been used to treat or ameliorate suchconditions. Furthermore, otherwise healthy individuals may takeadvantage of such therapies to prevent respiratory disorders fromarising. However, these have a number of shortcomings.

2.2.2 Therapy

Various therapies, such as Continuous Positive Airway Pressure (CPAP)therapy, Non-invasive ventilation (NIV) and Invasive ventilation (IV)have been used to treat one or more of the above respiratory disorders.

Continuous Positive Airway Pressure (CPAP) therapy has been used totreat Obstructive Sleep Apnea (OSA). The mechanism of action is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion, such as by pushing the soft palate andtongue forward and away from the posterior oropharyngeal wall. Treatmentof OSA by CPAP therapy may be voluntary, and hence patients may electnot to comply with therapy if they find devices used to provide suchtherapy one or more of: uncomfortable, difficult to use, expensive andaesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patientthrough the upper airways to assist the patient breathing and/ormaintain adequate oxygen levels in the body by doing some or all of thework of breathing. The ventilatory support is provided via anon-invasive patient interface. NIV has been used to treat CSR andrespiratory failure, in forms such as OHS, COPD, NMD and Chest Walldisorders. In some forms, the comfort and effectiveness of thesetherapies may be improved.

Invasive ventilation (IV) provides ventilatory support to patients thatare no longer able to effectively breathe themselves and may be providedusing a tracheostomy tube. In some forms, the comfort and effectivenessof these therapies may be improved.

2.2.3 Treatment Systems

These therapies may be provided by a treatment system or device. Suchsystems and devices may also be used to screen, diagnose, or monitor acondition without treating it.

A treatment system may comprise a Respiratory Pressure Therapy Device(RPT device), an air circuit, a humidifier, a patient interface, anddata management.

Another form of treatment system is a mandibular repositioning device.

2.2.3.1 Patient Interface

A patient interface may be used to interface respiratory equipment toits wearer, for example by providing a flow of air to an entrance to theairways. The flow of air may be provided via a mask to the nose and/ormouth, a tube to the mouth or a tracheostomy tube to the trachea of apatient. Depending upon the therapy to be applied, the patient interfacemay form a seal, e.g., with a region of the patient's face, tofacilitate the delivery of gas at a pressure at sufficient variance withambient pressure to effect therapy, e.g., at a positive pressure ofabout 10 cmH₂O relative to ambient pressure. For other forms of therapy,such as the delivery of oxygen, the patient interface may not include aseal sufficient to facilitate delivery to the airways of a supply of gasat a positive pressure of about 10 cmH₂O.

Certain other mask systems may be functionally unsuitable for thepresent field. For example, purely ornamental masks may be unable tomaintain a suitable pressure. Mask systems used for underwater swimmingor diving may be configured to guard against ingress of water from anexternal higher pressure, but not to maintain air internally at a higherpressure than ambient.

Certain masks may be clinically unfavourable for the present technologye.g. if they block airflow via the nose and only allow it via the mouth.

Certain masks may be uncomfortable or impractical for the presenttechnology if they require a patient to insert a portion of a maskstructure in their mouth to create and maintain a seal via their lips.

Certain masks may be impractical for use while sleeping, e.g. forsleeping while lying on one's side in bed with a head on a pillow.

The design of a patient interface presents a number of challenges. Theface has a complex three-dimensional shape. The size and shape of nosesand heads varies considerably between individuals. Since the headincludes bone, cartilage and soft tissue, different regions of the facerespond differently to mechanical forces. The jaw or mandible may moverelative to other bones of the skull. The whole head may move during thecourse of a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being oneor more of obtrusive, aesthetically undesirable, costly, poorly fitting,difficult to use, and uncomfortable especially when worn for longperiods of time or when a patient is unfamiliar with a system. Wronglysized masks can give rise to reduced compliance, reduced comfort andpoorer patient outcomes. Masks designed solely for aviators, masksdesigned as part of personal protection equipment (e.g. filter masks),SCUBA masks, or for the administration of anaesthetics may be tolerablefor their original application, but nevertheless such masks may beundesirably uncomfortable to be worn for extended periods of time, e.g.,several hours. This discomfort may lead to a reduction in patientcompliance with therapy. This is even more so if the mask is to be wornduring sleep.

CPAP therapy is highly effective to treat certain respiratory disorders,provided patients comply with therapy. If a mask is uncomfortable, ordifficult to use a patient may not comply with therapy. Since it isoften recommended that a patient regularly wash their mask, if a mask isdifficult to clean (e.g., difficult to assemble or disassemble),patients may not clean their mask and this may impact on patientcompliance.

While a mask for other applications (e.g. aviators) may not be suitablefor use in treating sleep disordered breathing, a mask designed for usein treating sleep disordered breathing may be suitable for otherapplications.

For these reasons, patient interfaces for delivery of CPAP during sleepform a distinct field.

2.2.3.1.1 Seal-Forming Structure

Patient interfaces may include a seal-forming structure. Since it is indirect contact with the patient's face, the shape and configuration ofthe seal-forming structure can have a direct impact on the effectivenessand comfort of the patient interface.

A patient interface may be partly characterised according to the designintent of where the seal-forming structure is to engage with the face inuse. In one form of patient interface, a seal-forming structure maycomprise a first sub-portion to form a seal around the left naris and asecond sub-portion to form a seal around the right naris. In one form ofpatient interface, a seal-forming structure may comprise a singleelement that surrounds both nares in use. Such single element may bedesigned to for example overlay an upper lip region and a nasal bridgeregion of a face. In one form of patient interface a seal-formingstructure may comprise an element that surrounds a mouth region in use,e.g. by forming a seal on a lower lip region of a face. In one form ofpatient interface, a seal-forming structure may comprise a singleelement that surrounds both nares and a mouth region in use. Thesedifferent types of patient interfaces may be known by a variety of namesby their manufacturer including nasal masks, full-face masks, nasalpillows, nasal puffs and oro-nasal masks.

A seal-forming structure that may be effective in one region of apatient's face may be inappropriate in another region, e.g. because ofthe different shape, structure, variability and sensitivity of theregions of the patient's face. For example, a seal on swimming gogglesthat overlays a patient's forehead may not be appropriate to use on apatient's nose.

Certain seal-forming structures may be designed for mass manufacturesuch that one design fit and be comfortable and effective for a widerange of different face shapes and sizes. To the extent to which thereis a mismatch between the shape of the patient's face, and theseal-forming structure of the mass-manufactured patient interface, oneor both must adapt in order for a seal to form. This can lead to patientdiscomfort.

A seal-forming structure which fits one person may not fit anotherperson. Furthermore, a design which fits a patient at one pressure, orin one position may not be suitable for other pressures or otherpositions. Some designs may leak when a patient moves, e.g. whilstasleep.

One type of seal-forming structure extends around the periphery of thepatient interface, and is intended to seal against the patient's facewhen force is applied to the patient interface with the seal-formingstructure in confronting engagement with the patient's face. Theseal-forming structure may include an air or fluid filled cushion, or amoulded or formed surface of a resilient seal element made of anelastomer such as a rubber. With this type of seal-forming structure, ifthe fit is not adequate, there will be gaps between the seal-formingstructure and the face, and additional force will be required to forcethe patient interface against the face in order to achieve a seal.

Another type of seal-forming structure incorporates a flap seal of thinmaterial positioned about the periphery of the mask so as to provide aself-sealing action against the face of the patient when positivepressure is applied within the mask. Like the previous style of sealforming portion, if the match between the face and the mask is not good,additional force may be required to achieve a seal, or the mask mayleak. Furthermore, if the shape of the seal-forming structure does notmatch that of the patient, it may crease or buckle in use, giving riseto leaks.

Furthermore, some manufacturing processes result in undesirable folds,creases or buckles in the seal-forming structure even when not in use.

Another type of seal-forming structure may comprise a friction-fitelement, e.g. for insertion into a naris, however some patients findthese uncomfortable.

Another form of seal-forming structure may use adhesive to achieve aseal. Some patients may find it inconvenient to constantly apply andremove an adhesive to their face.

A range of patient interface seal-forming structure technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT′ nasal pillows mask, SWIFT™ II nasal pillows mask,SWIFT™ LT nasal pillows mask, SWIFT™ FX nasal pillows mask and MIRAGELIBERTY™ full-face mask. The following patent applications, assigned toResMed Limited, describe examples of nasal pillows masks: InternationalPatent Application WO2004/073,778 (describing amongst other thingsaspects of the ResMed Limited SWIFT™ nasal pillows), US PatentApplication 2009/0044808 (describing amongst other things aspects of theResMed Limited SWIFT™ LT nasal pillows); International PatentApplications WO 2005/063,328 and WO 2006/130,903 (describing amongstother things aspects of the ResMed Limited MIRAGE LIBERTY™ full-facemask); International Patent Application WO 2009/052,560 (describingamongst other things aspects of the ResMed Limited SWIFT™ FX nasalpillows).

2.2.3.1.2 Positioning and Stabilising

A seal-forming structure of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus, a variety of techniques have been usedto position the seal-forming structure, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US PatentApplication Publication No. US 2010/0000534. However, the use ofadhesives may be uncomfortable for some.

Another technique is the use of one or more straps and/or stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

A respiratory pressure therapy (RPT) device may be used individually oras part of a system to deliver one or more of a number of therapiesdescribed above, such as by operating the device to generate a flow ofair for delivery to an interface to the airways. The flow of air may bepressurised. Examples of RPT devices include a CPAP device and aventilator.

Air pressure generators are known in a range of applications, e.g.industrial-scale ventilation systems. However, air pressure generatorsfor medical applications have particular requirements not fulfilled bymore generalised air pressure generators, such as the reliability, sizeand weight requirements of medical devices. In addition, even devicesdesigned for medical treatment may suffer from shortcomings, pertainingto one or more of: comfort, noise, ease of use, efficacy, size, weight,manufacturability, cost, and reliability.

An example of the special requirements of certain RPT devices isacoustic noise.

Table of noise output levels of prior RPT devices (one specimen only,measured using test method specified in ISO 3744 in CPAP mode at 10cmH₂O).

A-weighted sound Year RPT Device name pressure level dB(A) (approx.)C-Series Tango ™ 31.9 2007 C-Series Tango ™ with Humidifier 33.1 2007 S8Escape ™ II 30.5 2005 S8 Escape ™ II with H4i ™ Humidifier 31.1 2005 S9AutoSet ™ 26.5 2010 S9 AutoSet ™ with H5i Humidifier 28.6 2010

One known RPT device used for treating sleep disordered breathing is theS9 Sleep Therapy System, manufactured by ResMed Limited. Another exampleof an RPT device is a ventilator. Ventilators such as the ResMedStellar™ Series of Adult and Paediatric Ventilators may provide supportfor invasive and non-invasive non-dependent ventilation for a range ofpatients for treating a number of conditions such as but not limited toNMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator mayprovide support for invasive and non-invasive dependent ventilationsuitable for adult or paediatric patients for treating a number ofconditions. These ventilators provide volumetric and barometricventilation modes with a single or double limb circuit. RPT devicestypically comprise a pressure generator, such as a motor-driven bloweror a compressed gas reservoir, and are configured to supply a flow ofair to the airway of a patient. In some cases, the flow of air may besupplied to the airway of the patient at positive pressure. The outletof the RPT device is connected via an air circuit to a patient interfacesuch as those described above.

The designer of a device may be presented with an infinite number ofchoices to make. Design criteria often conflict, meaning that certaindesign choices are far from routine or inevitable. Furthermore, thecomfort and efficacy of certain aspects may be highly sensitive tosmall, subtle changes in one or more parameters.

2.2.3.3 Humidifier

Delivery of a flow of air without humidification may cause drying ofairways. The use of a humidifier with an RPT device and the patientinterface produces humidified gas that minimizes drying of the nasalmucosa and increases patient airway comfort. In addition, in coolerclimates warm air applied generally to the face area in and about thepatient interface is more comfortable than cold air.

A range of artificial humidification devices and systems are known,however they may not fulfil the specialised requirements of a medicalhumidifier.

Medical humidifiers are used to increase humidity and/or temperature ofthe flow of air in relation to ambient air when required, typicallywhere the patient may be asleep or resting (e.g. at a hospital). Amedical humidifier for bedside placement may be small. A medicalhumidifier may be configured to only humidify and/or heat the flow ofair delivered to the patient without humidifying and/or heating thepatient's surroundings. Room-based systems (e.g. a sauna, an airconditioner, or an evaporative cooler), for example, may also humidifyair that is breathed in by the patient, however those systems would alsohumidify and/or heat the entire room, which may cause discomfort to theoccupants. Furthermore medical humidifiers may have more stringentsafety constraints than industrial humidifiers.

While a number of medical humidifiers are known, they can suffer fromone or more shortcomings. Some medical humidifiers may provideinadequate humidification, some are difficult or inconvenient to use bypatients.

2.2.3.4 Data Management

There may be clinical reasons to obtain data to determine whether thepatient prescribed with respiratory therapy has been “compliant”, e.g.that the patient has used their RPT device according to one or more“compliance rules.” One example of a compliance rule for CPAP therapy isthat a patient, in order to be deemed compliant, is required to use theRPT device for at least four hours a night for at least 21 of 30consecutive days. In order to determine a patient's compliance, aprovider of the RPT device, such as a health care provider, may manuallyobtain data describing the patient's therapy using the RPT device,calculate the usage over a predetermined time period, and compare withthe compliance rule. Once the health care provider has determined thatthe patient has used their RPT device according to the compliance rule,the health care provider may notify a third party that the patient iscompliant.

There may be other aspects of a patient's therapy that would benefitfrom communication of therapy data to a third party or external system.

Existing processes to communicate and manage such data can be one ormore of costly, time-consuming, and error-prone.

2.2.3.5 Vent Technologies

Some forms of treatment systems may include a vent to allow the washoutof exhaled carbon dioxide. The vent may allow a flow of gas from aninterior space of a patient interface, e.g., the plenum chamber, to anexterior of the patient interface, e.g., to ambient.

The vent may comprise an orifice and gas may flow through the orifice inuse of the mask. Many such vents are noisy. Others may become blocked inuse and thus provide insufficient washout. Some vents may be disruptiveof the sleep of a bed partner 1100 of the patient 1000, e.g. throughnoise or focussed airflow.

ResMed Limited has developed a number of improved mask venttechnologies. See International Patent Application Publication No. WO1998/034,665; International Patent Application Publication No. WO2000/078,381; U.S. Pat. No. 6,581,594; US Patent Application PublicationNo. US 2009/0050156; US Patent Application Publication No. 2009/0044808.

Table of noise of prior masks (ISO 17510-2: 2007, 10 cmH₂O pressure at 1m) A-weighted A-weighted sound power sound pressure level dB(A) dB(A)Year Mask name Mask type (uncertainty) (uncertainty) (approx.) Glue-on(*) nasal 50.9 42.9 1981 ResCare nasal 31.5 23.5 1993 standard (*)ResMed nasal 29.5 21.5 1998 Mirage ™ (*) ResMed nasal 36 (3) 28 (3) 2000UltraMirage ™ ResMed nasal 32 (3) 24 (3) 2002 Mirage Activa ™ ResMednasal 30(3) 22 (3) 2008 Mirage Micro ™ ResMed nasal 29 (3) 22 (3) 2008Mirage ™ SoftGel ResMed nasal 26 (3) 18 (3) 2010 Mirage ™ FX ResMednasal 37   29   2004 Mirage Swift ™ pillows (*) ResMed nasal 28 (3) 20(3) 2005 Mirage Swift ™ pillows II ResMed nasal 25 (3) 17 (3) 2008Mirage Swift ™ pillows LT ResMed AirFit nasal 21 (3) 13 (3) 2014 P10pillows ((*) one specimen only, measured using test method specified inISO 3744 in CPAP mode at 10 cmH₂O)

Sound pressure values of a variety of objects are listed below

A-weighted sound Object pressure dB(A) Notes Vacuum cleaner: Nilfisk 68ISO 3744 at 1 m Walter Broadly Litter Hog: B+ distance GradeConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 20

2.2.4 Screening, Diagnosis, and Monitoring Systems

Polysomnography (PSG) is a conventional system for diagnosis andmonitoring of cardio-pulmonary disorders, and typically involves expertclinical staff to apply the system. PSG typically involves the placementof 15 to 20 contact sensors on a patient in order to record variousbodily signals such as electroencephalography (EEG), electrocardiography(ECG), electrooculography (EOG), electromyography (EMG), etc. PSG forsleep disordered breathing has involved two nights of observation of apatient in a clinic, one night of pure diagnosis and a second night oftitration of treatment parameters by a clinician. PSG is thereforeexpensive and inconvenient. In particular it is unsuitable for homescreening/diagnosis/monitoring of sleep disordered breathing.

Clinical experts may be able to diagnose, or monitor patients adequatelybased on visual observation of PSG signals. However, there arecircumstances where a clinical expert may not be available, or aclinical expert may not be affordable. Different clinical experts maydisagree on a patient's condition. In addition, a given clinical expertmay apply a different standard at different times.

3 BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the diagnosis, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost,efficacy, ease of use and manufacturability.

A first aspect of the present technology relates to apparatus used inthe diagnosis, amelioration, treatment or prevention of a respiratorydisorder.

Another aspect of the present technology relates to methods used in thediagnosis, amelioration, treatment or prevention of a respiratorydisorder.

An aspect of certain forms of the present technology is to providemethods and/or apparatuses that improve the compliance of patients withrespiratory therapy.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including atextile membrane.

In one form, the textile membrane is air impermeable.

Another aspect of the present technology relates to a process ofmanufacturing a patient interface utilizing a flat textile composite tocreate a textile membrane having a curved shape.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including atextile membrane where the seal-forming structure has no (or few)buckles or creases.

Another aspect of the present technology is a patient interfacecomprising a textile membrane including a knitted textile material.

In one form the knitted textile material is warp knitted.

In one form the knitted textile material is weft knitted.

In one form, the textile membrane is stretchy (e.g., equally stretchy)in both vertical and horizontal directions.

In one form, the textile membrane is more stretchy in the horizontaldirection than in the vertical direction.

Another aspect of the present technology pertains to a patient interfacehaving a wide fit range.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including asealing portion (e.g., comprising a textile material) that is held intension prior to use.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure includingan untensioned textile membrane that is without creases, folds, wrinklesand/or buckles in an outer surface of the textile membrane

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including atextile membrane having a bridge portion that is slack and/or buckledwith excess material.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising a cushion assembly including: 1) a plenum chamberat least partially forming a cavity pressurisable to a therapeuticpressure of at least 6 cmH₂O above ambient air pressure, said plenumchamber including a plenum chamber inlet port sized and structured toreceive a flow of air at the therapeutic pressure for breathing by apatient; and 2) a seal-forming structure having a textile membraneconstructed and arranged to form a pressure-assisted seal with a regionof the patient's face surrounding an entrance to the patient's airwaysinferior to a nasal bridge region of the patient's face, said textilemembrane having a hole formed therein such that the flow of air at saidtherapeutic pressure is delivered to at least an entrance to thepatient's nares, the seal-forming structure constructed and arranged tomaintain said therapeutic pressure in the cavity throughout thepatient's respiratory cycle in use.

In examples: (a) the seal-forming structure includes a flexible supportstructure to hold the textile membrane in a predefined curved shape, thetextile membrane being configured to seal with an underside of thepatient's nose including the patient's subnasale and the patient'spronasale; (b) the seal-forming structure includes a seal biasingportion extending along a perimeter of the cushion assembly at least inlateral regions of the cushion assembly, the seal biasing portion beingless rigid than adjacent portions of the support structure such that theseal biasing portion is configured to inflate upon pressurization of thecavity in use thereby allowing the seal biasing portion to extend areach of the textile membrane and decouple the textile membrane fromexternal forces applied to the plenum chamber when activated in use; and(c) the seal biasing portion is configured to extend the reach of thetextile membrane a greater distance in the lateral regions of thecushion assembly than in at least a portion of a central region of thecushion assembly such that when the seal biasing portion is activated inuse the central region forms a bending or flexing area thereby allowingthe textile membrane in the lateral regions to cradle or pinch thepatient's nasal alar.

In further examples: (a) the textile membrane in the lateral regions isconfigured to extend in a posterosuperior direction and a left-rightdirection to facilitate cradling or pinching the patient's nasal alarwhen the seal biasing portion is activated in use; (b) in use, thetextile membrane is configured to press against the patient's face suchthat the patient's nose is not received in the cavity; (c) the sealbiasing portion is omitted in at least a portion of the central portionof the cushion assembly; (d) the seal biasing portion extends around anentire perimeter of the cushion assembly; (e) a size of the seal biasingportion varies around the perimeter of the cushion assembly; (f) theseal biasing portion is larger in the lateral regions and smaller in thecentral region of the cushion assembly; and (g) the size of the sealbiasing portion tapers from a larger seal biasing portion in the lateralregions to a smaller seal biasing portion toward the central region ofthe cushion assembly.

In further examples: (a) the seal biasing portion comprises an indentedchannel or recess; (b) the seal biasing portion comprises an externalprotrusion; (c) the seal biasing portion comprises at least one fold,pleat, or undulation; (d) the at least one fold, pleat, or undulationallows the textile membrane to telescope towards the patient's face inuse when the seal biasing portion is activated; (e) the seal biasingportion comprises a plurality of folds, pleats or undulations; (f) theplurality of folds, pleats or undulations form a sinusoidal wave incross section; and (g) the seal biasing portion comprises a step and awing, the step and wing being angled with respect to one another.

In further examples: (a) the seal biasing portion is disposed betweenthe support structure and the textile membrane; (b) the seal biasingportion is disposed between the plenum chamber and the supportstructure; (c) the cushion assembly includes a stem that projects fromthe plenum chamber to support the seal-forming structure; (d) the sealbiasing portion extends through the lateral regions of the cushionassembly at an angle α with respect to a plane extending along ananterior side of the cushion assembly; and (e) the angle α is between30°-60°; (f) the seal-forming structure is arranged such that thetextile membrane has a saddle shape configured to accommodate theunderside of the patient's nose in use.

In further examples: (a) the support structure and the seal biasingportion comprise silicone; (b) the textile membrane is attached to thesupport structure along an outer perimeter of the textile membrane suchthat the textile membrane extends radially inwardly beyond the supportstructure; (c) the support structure comprises silicone and the textilemembrane is molded to an inner edge of the support structure; (d) the atleast one hole in the textile membrane comprises two holes, and a bridgeportion is disposed between the two holes in the textile membrane; (e)the textile membrane comprises a textile membrane, the textile membranecomprising a membrane layer applied to a textile material to make thetextile material substantially air impermeable; and (f) the plenumchamber comprises silicone and is formed in one piece with the supportstructure.

In further examples: (a) the patient interface further comprises apositioning and stabilising structure to provide a force to hold theseal-forming structure in a therapeutically effective position on thepatient's head, the positioning and stabilising structure comprising atie, the tie being constructed and arranged so that at least a portionoverlies a region of the patient's head superior to an otobasionsuperior of the patient's head in use; (b) the patient interface furthercomprises a vent structure to allow a continuous flow of gases exhaledby the patient from an interior of the cavity to ambient, said ventstructure being sized and shaped to maintain the therapeutic pressure inthe cavity in use; and (c) the plenum chamber and seal-forming structureform a nasal cushion.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising a cushion assembly including: 1) a plenum chamberat least partially forming a cavity pressurisable to a therapeuticpressure of at least 6 cmH₂O above ambient air pressure, said plenumchamber including a plenum chamber inlet port sized and structured toreceive a flow of air at the therapeutic pressure for breathing by apatient; and 2) a seal-forming structure having a sealing portionconstructed and arranged to form a pressure-assisted seal with a regionof the patient's face surrounding an entrance to the patient's airwaysinferior to a nasal bridge region of the patient's face, said sealingportion having a hole formed therein such that the flow of air at saidtherapeutic pressure is delivered to at least an entrance to thepatient's nares, the seal-forming structure constructed and arranged tomaintain said therapeutic pressure in the cavity throughout thepatient's respiratory cycle in use.

In examples: (a) the seal-forming structure includes a flexible supportstructure to support the sealing portion, the sealing portion beingconfigured to seal with an underside of the patient's nose including thepatient's subnasale and the patient's pronasale; (b) the seal-formingstructure includes a seal biasing portion disposed with the sealingportion along a posterior patient-facing surface of the cushionassembly, the seal biasing portion including at least one of fold, pleator undulation extending between the sealing portion and the supportstructure; and (c) the seal biasing portion is configured to inflateupon pressurization of the cavity in use thereby causing the sealingportion to extend or telescope beyond other portions of the posteriorpatient-facing surface of the cushion assembly in a direction towards atleast a portion of the patient's face.

In further examples: (a) the seal biasing portion comprises a pluralityof folds, pleats or undulations that form a sinusoidal wave in crosssection; (b) the seal biasing portion is disposed at least in lateralregions of the cushion assembly; (c) the sealing portion is configuredto extend or telescope a greater distance in the lateral regions of thecushion assembly than in a central region of the cushion assembly suchthat when the seal biasing portion is activated in use the centralregion forms a bending or flexing area thereby allowing the sealingportion in the lateral regions to cradle or pinch the patient's nasalalar; (d) a size of the seal biasing portion varies around the perimeterof the cushion assembly; (e) the seal biasing portion is larger in thelateral regions and smaller in the central region of the cushionassembly; (f) the seal biasing portion extends around an entireperimeter of the cushion assembly; (g) the seal biasing portion isomitted in at least a portion of the central portion of the cushionassembly; (h) the support structure and the seal biasing portioncomprise silicone; and (i) the sealing portion comprises a textilemembrane.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising a cushion assembly including: 1) a plenum chamberat least partially forming a cavity pressurisable to a therapeuticpressure of at least 6 cmH₂O above ambient air pressure, said plenumchamber including a plenum chamber inlet port sized and structured toreceive a flow of air at the therapeutic pressure for breathing by apatient; and 2) a seal-forming structure having a sealing portionconstructed and arranged to form a pressure-assisted seal with a regionof the patient's face surrounding an entrance to the patient's airwaysinferior to a nasal bridge region of the patient's face, said sealingportion having a hole formed therein such that the flow of air at saidtherapeutic pressure is delivered to at least an entrance to thepatient's nares, the seal-forming structure constructed and arranged tomaintain said therapeutic pressure in the cavity throughout thepatient's respiratory cycle in use.

In examples: (a) the seal-forming structure includes a flexible supportstructure to support the sealing portion; (b) the plenum chamber inletport is formed in an anterior side of the plenum chamber, the anteriorside of the plenum chamber including connector structure adapted toconnect to an air supply tube; and (c) the anterior side of the plenumchamber includes a connector gusset comprising one or more folds, pleatsor undulations adjacent to and extending around the inlet port that areconfigured to decouple the seal-forming structure from external forcesexerted on the air supply tube.

In further examples: (a) the patient interface further comprises an airsupply tube connected to the anterior side of the plenum chamber and influid communication with the inlet port; (b) the sealing portioncomprises a textile membrane configured to seal with an underside of thepatient's nose including the patient's subnasale and the patient'spronasale; and (c) the patient interface further comprises a positioningand stabilising structure to provide a force to hold the seal-formingstructure in a therapeutically effective position on the patient's head,the positioning and stabilising structure comprising a tie, the tiebeing constructed and arranged so that at least a portion overlies aregion of the patient's head superior to an otobasion superior of thepatient's head in use.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising: 1) a plenum chamber at least partially forming acavity pressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, said plenum chamber being adapted to receive aflow of air at the therapeutic pressure for breathing by a patient; and2) a seal-forming structure having a textile membrane constructed andarranged to form a seal with a region of the patient's face surroundingan entrance to the patient's airways, said textile membrane having ahole formed therein such that the flow of air at said therapeuticpressure is delivered to at least an entrance to the patient's nares,the seal-forming structure constructed and arranged to maintain saidtherapeutic pressure in the cavity throughout the patient's respiratorycycle in use.

In examples: (a) the seal-forming structure includes a support structureto support the textile membrane, the support structure being configuredto connect to the plenum chamber; and (b) the textile membrane isattached to the support structure along an outer perimeter of thetextile membrane in a manner that causes the textile membrane to be intension prior to use.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising: 1) a plenum chamber at least partially forming acavity pressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, said plenum chamber including a plenum chamberinlet port sized and structured to receive a flow of air at thetherapeutic pressure for breathing by a patient; and 2) a seal-formingstructure having a textile membrane constructed and arranged to form aseal with a region of the patient's face surrounding an entrance to thepatient's airways, said textile membrane having a hole formed thereinsuch that the flow of air at said therapeutic pressure is delivered toat least an entrance to the patient's nares, the seal-forming structureconstructed and arranged to maintain said therapeutic pressure in thecavity throughout the patient's respiratory cycle in use. Theseal-forming structure may include a flexible support structure tosupport the textile membrane, the support structure being connected tothe plenum chamber, the support structure being stiffer than the textilemembrane. In use, the textile membrane may be configured to pressagainst the patient's face such that the patient's nose is not receivedin the cavity. The textile membrane may be attached to the supportstructure along an outer perimeter of the textile membrane such thattextile membrane extends radially inwardly beyond the support structure.

In examples: (a) the plenum chamber and the support structure comprisesilicone and form a one piece structure having a first lateral supportsection with a first thickness and a second centrally disposed nose basesection with a second thickness that is less than the first thickness,and the nose base section is configured to fold or form a pivot pointupon engagement of the textile membrane with the patient's face therebyallowing left and right lateral sides of the support structure to deforminwardly to cradle the patient's nose; (b) the support structureincludes an underlying cushion; (c) the support structure comprisesfoam; (d) the support structure comprises silicone and the textilemembrane is molded to an inner edge of the support structure; (e) thetextile membrane has a dome shape in a corner region of the textilemembrane; (f) the textile membrane has a saddle shape in a lower centralregion of the textile membrane that is configured to seal against thepatient's subnasale in use.

In further examples: (a) the textile membrane comprises a membrane layerapplied to a textile material to make the textile material substantiallyair impermeable; (b) the textile membrane has a thickness in the rangeof 0.3 mm to 0.5 mm; (c) the membrane layer has a thickness in the rangeof 0.05 mm to 0.1 mm; (d) the textile material is weft knit; (e) theweight of the textile material is in the range of 105 gsm to 120 gsm;(f) the machine gauge of the textile material is in the range of 44 GGto 60 GG; (g) the textile material has a melange aesthetic; (h) thetextile material has a solid color aesthetic; (i) the membrane layercomprises silicone; (j) the textile material comprises nylon, spandex,or polyester; (k) in use, the therapeutic pressure in the cavity urgesthe textile membrane towards the patient's face; (l) the plenum chambercomprises silicone and is formed in one piece with the supportstructure.

In further examples: (a) the patient interface further comprises apositioning and stabilising structure to provide a force to hold theseal-forming structure in a therapeutically effective position on thepatient's head, the positioning and stabilising structure comprising atie, the tie being constructed and arranged so that at least a portionoverlies a region of the patient's head superior to an otobasionsuperior of the patient's head in use; (b) the patient interface furthercomprises a vent structure to allow a continuous flow of gases exhaledby the patient from an interior of the cavity to ambient, said ventstructure being sized and shaped to maintain the therapeutic pressure inthe cavity in use; (c) the plenum chamber and seal-forming structureform an oro-nasal cushion assembly; (d) the plenum chamber andseal-forming structure form a nasal cushion.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising: 1) a plenum chamber at least partially forming acavity pressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, said plenum chamber including a plenum chamberinlet port sized and structured to receive a flow of air at thetherapeutic pressure for breathing by a patient; and 2) a seal-formingstructure having a textile membrane constructed and arranged to form aseal with a region of the patient's face surrounding an entrance to thepatient's airways, said textile membrane having at least one hole formedtherein such that the flow of air at said therapeutic pressure isdelivered to at least an entrance to the patient's nares, theseal-forming structure constructed and arranged to maintain saidtherapeutic pressure in the cavity throughout the patient's respiratorycycle in use. The seal-forming structure may include a flexible supportstructure to support the textile membrane, the support structure beingstiffer than the textile membrane, the support structure being connectedto the plenum chamber. At a transition portion, the textile membrane maybe attached to the support structure along an outer edge of the textilemembrane and an inner edge of the support structure such that textilemembrane extends radially inwardly beyond the support structure. At thetransition portion, both the support structure and the textile membranemay extend along a curve in a direction from an anterior side of theseal-forming structure to a posterior patient-facing side of theseal-forming structure.

In examples: (a) at the transition portion, the support structure andthe textile membrane have substantially the same radius of curvature;(b) the textile membrane extends continuously along the curve from thetransition portion to the inner edge of the textile membrane; (c) inuse, the textile membrane may be configured to press against thepatient's face such that the patient's nose is not received in thecavity; (d) the at least one hole in the textile membrane comprises twoholes, and a bridge portion is disposed between the two holes in thetextile membrane; (e) the support structure comprises silicone and thetextile membrane is molded to an inner edge of the support structure;(f) the seal-forming structure has a seamless transition along an outersurface thereof from the support structure to the textile membrane.

In further examples: (a) the textile membrane comprises a textilematerial and a membrane layer applied thereto to make the textilematerial substantially air impermeable; (b) the textile membrane has athickness in the range of 0.3 mm to 0.5 mm; (c) the textile material isweft knit; (d) the membrane layer comprises silicone; (e) the textilematerial comprises nylon, spandex, or polyester; (f) in use thetherapeutic pressure in the cavity urges the textile membrane towardsthe patient's face; (g) the plenum chamber and seal-forming structureform an oro-nasal cushion assembly; (h) the plenum chamber andseal-forming structure form a nasal cushion.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of air at a continuously positive pressurewith respect to ambient air pressure to an entrance to a patient'sairways including at least entrance of a patient's nares, wherein thepatient interface is configured to maintain a therapy pressure in arange of about 4 cmH₂O to about 30 cmH₂O above ambient air pressure inuse, throughout a patient's respiratory cycle, while the patient issleeping, to ameliorate sleep disordered breathing; said patientinterface comprising: 1) a plenum chamber at least partially forming acavity pressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, said plenum chamber including a plenum chamberinlet port sized and structured to receive a flow of air at thetherapeutic pressure for breathing by a patient; and 2) a seal-formingstructure having a textile membrane constructed and arranged to form aseal with a region of the patient's face surrounding an entrance to thepatient's airways, said textile membrane having at least one hole formedtherein such that the flow of air at said therapeutic pressure isdelivered to at least an entrance to the patient's nares, theseal-forming structure constructed and arranged to maintain saidtherapeutic pressure in the cavity throughout the patient's respiratorycycle in use. The textile membrane may comprise a textile material and amembrane layer applied thereto to make the textile materialsubstantially air impermeable, the textile material may be a weft knittextile. The seal-forming structure may include a flexible supportstructure to support the textile membrane, the support structure may beconnected to the plenum chamber, and the support structure may bestiffer than the textile membrane. The textile membrane may be attachedto the support structure along an outer perimeter of the textilemembrane such that textile membrane extends radially inwardly beyond thesupport structure. In use, the textile membrane may be configured topress against the patient's face such that the patient's nose is notreceived in the cavity. The textile membrane may have a dome shape in acorner region of the textile membrane configured to seal against thepatient's subalare, and a saddle shape at a lower central region of thetextile membrane configured to seal against the patient's subnasale.

In examples: (a) in use, the therapeutic pressure in the cavity urgesthe textile membrane towards the patient's face to assist the textilemembrane in forming a seal with the patient's face; (b) the at least onehole in the textile membrane comprises two holes, a bridge portion isdisposed between the two holes in the textile membrane, and the bridgeportion is buckled with excess material to allow the textile membrane toexpand to accommodate different size noses; (c) the support structurecomprises silicone and the textile membrane is molded to an inner edgeof the support structure; (d) the plenum chamber comprises silicone andis formed in one piece with the support structure; (e) the textilemembrane is attached to the support structure in a manner that causesthe textile membrane to be in tension prior to use; (f) a first regionof the textile membrane is in tension prior to use and a second regionof the textile membrane is untensioned prior to use.

In further examples: (a) the textile membrane has four-way elasticity;(b) the textile membrane has a first elasticity in lateral left-rightdirection and a second different elasticity in a superior-inferiordirection, wherein the elasticity in the first direction is greater thanthe elasticity in the second direction; (c) the membrane layer comprisessilicone; (d) the textile material comprises nylon, spandex, orpolyester; (e) the plenum chamber and seal-forming structure form anoro-nasal cushion assembly; (f) the plenum chamber and seal-formingstructure form a nasal cushion.

Another aspect of the present technology relates to a method of forminga cushion assembly for a patient interface, the cushion assembly beingconfigured for sealed delivery of a flow of air at a continuouslypositive pressure with respect to ambient air pressure to an entrance toa patient's airways including at least entrance of a patient's nares,wherein the cushion assembly is configured to maintain a therapypressure in a range of about 4 cmH₂O to about 30 cmH₂O above ambient airpressure in use, throughout a patient's respiratory cycle, while thepatient is sleeping, to ameliorate sleep disordered breathing; saidmethod comprising: 1) forming an airtight textile composite by applyingan air impermeable material to a textile material, the textile compositehaving a flat shape; 2) cutting the textile composite to desireddimensions according to a particular cushion assembly type to be used;and 3) overmolding a flexible support structure onto the cut textilecomposite to form a seal-forming structure having a textile membranesuch that the textile membrane is attached to the support structurealong an outer edge of the textile membrane and an inner edge of thesupport structure. In the overmolding step, the textile composite may beheld in place by vacuum so as to have a non-flat shape duringovermolding thereby imparting a curved non-flat shape to the textilemembrane. No wrinkles, creases, folds and/or buckles are formed in thetextile membrane.

In examples: (a) the seal-forming structure has a seamless transitionalong an outer surface thereof from the support structure to the textilemembrane; (b) at a transition portion, the textile membrane is attachedto the support structure along an outer edge of the textile membrane andan inner edge of the support structure such that textile membraneextends radially inwardly beyond the support structure, and at thetransition portion, both the support structure and the textile membraneextend along a curve in a direction from an anterior side of theseal-forming structure to a posterior patient-facing side of theseal-forming structure; (c) two holes are formed in the textilemembrane, and a bridge portion is disposed between the two holes in thetextile membrane, and the bridge portion is buckled with excess materialto allow the textile membrane to expand to accommodate different sizenoses; (d) the support structure comprises silicone.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including asupport structure and a sealing portion, the support structuresupporting the sealing portion, wherein the sealing portion is attachedto the support structure along an outer perimeter of the sealing portionsuch that the sealing portion extends radially inwardly beyond thesupport structure, and wherein, in use, the sealing portion isconfigured to press against the patient's face such that the patient'snose is not received in the cavity and the sealing portion is in tensiondue to reactive stress of the support structure and/or a resilientstretch characteristic of the textile which thereby causes the sealingportion to exert a force against the patient's face.

According to a further aspect of the present technology, the sealingportion comprises textile. In a further example, the patient interfacecomprises a plenum chamber and the support structure is configured toconnect to the plenum chamber, the plenum chamber at least partiallyforming a cavity pressurisable to a therapeutic pressure of at least 6cmH₂O above ambient air pressure, the plenum chamber including a plenumchamber inlet port sized and structured to receive a flow of air at thetherapeutic pressure for breathing by a patient. In a further example,the sealing portion is constructed and arranged to form a seal with aregion of the patient's face surrounding an entrance to the patient'sairways, the sealing portion having a hole formed therein such that theflow of air at the therapeutic pressure is delivered to at least anentrance to the patient's nares, the seal-forming structure beingconstructed and arranged to maintain the therapeutic pressure in thecavity throughout the patient's respiratory cycle in use. In a furtherexample, the support structure comprise silicone and/or a thermoplasticelastomer.

According to a further aspect of the present technology, a wallstructure of the support structure between the sealing portion and theplenum chamber has a first section with a first thickness and a secondsection with a second thickness that is different than the firstthickness.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including asupport structure and a sealing portion, the support structuresupporting the sealing portion, wherein the sealing portion is attachedto the support structure along an outer perimeter of the sealing portionin a manner that causes the sealing portion to be in tension prior touse.

According to a further aspect of the present technology, the sealingportion comprising a textile material. In a further example, the patientinterface comprises a plenum chamber and the support structure isconfigured to connect to the plenum chamber, the plenum chamber at leastpartially forming a cavity pressurisable to a therapeutic pressure of atleast 6 cmH₂O above ambient air pressure, the plenum chamber including aplenum chamber inlet port sized and structured to receive a flow of airat the therapeutic pressure for breathing by a patient. In a furtherexample, the sealing portion is constructed and arranged to form a sealwith a region of the patient's face surrounding an entrance to thepatient's airways, the sealing portion having a hole formed therein suchthat the flow of air at the therapeutic pressure is delivered to atleast an entrance to the patient's nares, the seal-forming structurebeing constructed and arranged to maintain the therapeutic pressure inthe cavity throughout the patient's respiratory cycle in use. In afurther example, the support structure comprise silicone and/or athermoplastic elastomer.

Another aspect of the present technology relates to a seal-formingstructure of a patient interface, the seal-forming structure including asupport structure and a sealing portion, the support structuresupporting the sealing portion, wherein the sealing portion comprises atextile material and is attached to the support structure along an outerperimeter of the sealing portion, wherein the support structure is morerigid than the sealing portion, the support structure having a firstsection with a first thickness and a second section with a secondthickness that is different than the first thickness.

According to a further aspect of the present technology, the supportstructure comprises silicone and/or a thermoplastic elastomer, thepatient interface comprises a plenum chamber and the support structureis configured to connect to the plenum chamber, the plenum chamber atleast partially forming a cavity pressurisable to a therapeutic pressureof at least 6 cmH₂O above ambient air pressure, the plenum chamberincluding a plenum chamber inlet port sized and structured to receive aflow of air at the therapeutic pressure for breathing by a patient. In afurther example, the sealing portion is constructed and arranged to forma seal with a region of the patient's face surrounding an entrance tothe patient's airways, the sealing portion having a hole formed thereinsuch that the flow of air at the therapeutic pressure is delivered to atleast an entrance to the patient's nares, the seal-forming structurebeing constructed and arranged to maintain the therapeutic pressure inthe cavity throughout the patient's respiratory cycle in use.

Another aspect of one form of the present technology is a patientinterface that is moulded or otherwise constructed with a perimetershape which is complementary to that of an intended wearer.

An aspect of one form of the present technology is a method ofmanufacturing the apparatus.

An aspect of certain forms of the present technology is a medical devicethat is easy to use, e.g. by a person who does not have medicaltraining, by a person who has limited dexterity, vision or by a personwith limited experience in using this type of medical device.

An aspect of one form of the present technology is a patient interfacethat may be washed in a home of a patient, e.g., in soapy water, withoutrequiring specialised cleaning equipment.

Another aspect of the present technology relates to a treatment systemused for treatment of sleep disordered breathing, comprising: 1) thepatient interface according to any of the above aspects; 2) arespiratory pressure therapy (RPT) device to supply breathable gas atpositive pressure; and 3) an air delivery tube to pass the breathablegas from the RPT device to the patient interface.

The methods, systems, devices and apparatus described may be implementedso as to improve the functionality of a processor, such as a processorof a specific purpose computer, respiratory monitor and/or a respiratorytherapy apparatus. Moreover, the described methods, systems, devices andapparatus can provide improvements in the technological field ofautomated management, monitoring and/or treatment of respiratoryconditions, including, for example, sleep disordered breathing.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

4.1 Treatment Systems

FIG. 1A shows a system including a patient 1000 wearing a patientinterface 3000, in the form of nasal pillows, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device4000 is humidified in a humidifier 5000, and passes along an air circuit4170 to the patient 1000. A bed partner 1100 is also shown. The patientis sleeping in a supine sleeping position.

FIG. 1B shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a nasal mask, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device ishumidified in a humidifier 5000, and passes along an air circuit 4170 tothe patient 1000.

FIG. 1C shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a full-face mask, receiving a supply ofair at positive pressure from an RPT device 4000. Air from the RPTdevice is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000. The patient is sleeping in a sidesleeping position.

4.2 Respiratory System and Facial Anatomy

FIG. 2A shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2B shows a view of a human upper airway including the nasal cavity,nasal bone, lateral nasal cartilage, greater alar cartilage, nostril,lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

FIG. 2C is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermilion, lowervermilion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion. Also indicated are the directionssuperior, inferior, radially inward and radially outward.

FIG. 2D is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, alar crest point,otobasion superior and otobasion inferior. Also indicated are thedirections superior & inferior, and anterior & posterior.

FIG. 2E is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated. The coronalplane is also indicated.

FIG. 2F shows a base view of a nose with several features identifiedincluding naso-labial sulcus, lip inferior, upper Vermilion, naris,subnasale, columella, pronasale, the major axis of a naris and themidsagittal plane.

FIG. 2G shows a side view of the superficial features of a nose.

FIG. 2H shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage, sesamoid cartilage, nasal bone, epidermis, adipose tissue,frontal process of the maxilla and fibrofatty tissue.

FIG. 2I shows a medial dissection of a nose, approximately severalmillimeters from the midsagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage.

FIG. 2J shows a front view of the bones of a skull including thefrontal, nasal and zygomatic bones. Nasal concha are indicated, as arethe maxilla, and mandible.

FIG. 2K shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter, sternocleidomastoidand trapezius.

FIG. 2L shows an anterolateral view of a nose.

4.3 Patient Interface

FIG. 3A shows a patient interface in the form of a nasal mask inaccordance with one form of the present technology.

FIG. 3B shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3C.

FIG. 3C shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3B.

FIG. 3D shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a value of zero.

FIG. 3E shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3F.

FIG. 3F shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3E.

FIG. 3G shows a cushion for a mask that includes two pillows. Anexterior surface of the cushion is indicated. An edge of the surface isindicated. Dome and saddle regions are indicated.

FIG. 3H shows a cushion for a mask. An exterior surface of the cushionis indicated. An edge of the surface is indicated. A path on the surfacebetween points A and B is indicated. A straight line distance between Aand B is indicated. Two saddle regions and a dome region are indicated.

FIG. 3I shows the surface of a structure, with a one dimensional hole inthe surface. The illustrated plane curve forms the boundary of a onedimensional hole.

FIG. 3J shows a cross-section through the structure of FIG. 3I. Theillustrated surface bounds a two dimensional hole in the structure ofFIG. 3I.

FIG. 3K shows a perspective view of the structure of FIG. 3I, includingthe two dimensional hole and the one dimensional hole. Also shown is thesurface that bounds a two dimensional hole in the structure of FIG. 3I.

FIG. 3L shows a mask having an inflatable bladder as a cushion.

FIG. 3M shows a cross-section through the mask of FIG. 3L, and shows theinterior surface of the bladder. The interior surface bounds the twodimensional hole in the mask.

FIG. 3N shows a further cross-section through the mask of FIG. 3L. Theinterior surface is also indicated.

FIG. 3O illustrates a left-hand rule.

FIG. 3P illustrates a right-hand rule.

FIG. 3Q shows a left ear, including the left ear helix.

FIG. 3R shows a right ear, including the right ear helix.

FIG. 3S shows a right-hand helix.

FIG. 3T shows a view of a mask, including the sign of the torsion of thespace curve defined by the edge of the sealing membrane in differentregions of the mask.

FIG. 3U shows a view of a plenum chamber 3200 showing a sagittal planeand a mid-contact plane.

FIG. 3V shows a view of a posterior of the plenum chamber of FIG. 3U.The direction of the view is normal to the mid-contact plane. Thesagittal plane in FIG. 3V bisects the plenum chamber into left-hand andright-hand sides.

FIG. 3W shows a cross-section through the plenum chamber of FIG. 3V, thecross-section being taken at the sagittal plane shown in FIG. 3V. A‘mid-contact’ plane is shown. The mid-contact plane is perpendicular tothe sagittal plane. The orientation of the mid-contact plane correspondsto the orientation of a chord 3210 which lies on the sagittal plane andjust touches the cushion of the plenum chamber at two points on thesagittal plane: a superior point 3220 and an inferior point 3230.Depending on the geometry of the cushion in this region, the mid-contactplane may be a tangent at both the superior and inferior points.

FIG. 3X shows the plenum chamber 3200 of FIG. 3U in position for use ona face. The sagittal plane of the plenum chamber 3200 generallycoincides with the midsagittal plane of the face when the plenum chamberis in position for use. The mid-contact plane corresponds generally tothe ‘plane of the face’ when the plenum chamber is in position for use.In FIG. 3X the plenum chamber 3200 is that of a nasal mask, and thesuperior point 3220 sits approximately on the sellion, while theinferior point 3230 sits on the lip superior.

4.4 RPT Device

FIG. 4A shows an RPT device in accordance with one form of the presenttechnology.

4.5 Patient Interface According to the Present Technology

FIG. 5 is a perspective view of a patient interface according to anexample of the present technology worn by a patient.

FIG. 6 is a perspective view of a patient interface according to anotherexample of the present technology worn by a patient.

FIG. 7 is a cross-sectional view of the positioning and stabilisingstructure along the line 7-7 in FIG. 6.

FIG. 8 is an enlarged view of a portion of the positioning andstabilising structure of FIG. 7.

FIG. 9 is an enlarged view of a portion of the positioning andstabilising structure of FIG. 7.

FIG. 10 is a front view of the cushion assembly of FIG. 5 positioned ona patient's face.

FIG. 11 is a front view of the cushion assembly of FIG. 5.

FIG. 12 is a top perspective view of the cushion assembly of FIG. 5.

FIG. 13 is a top view of the cushion assembly of FIG. 5.

FIG. 14 is a side view of the cushion assembly of FIG. 5.

FIG. 15 is a front view of the cushion assembly of FIG. 5.

FIG. 16 is a side view of the cushion assembly of FIG. 5.

FIG. 17 is a top view of the cushion assembly of FIG. 5.

FIG. 18 is a front view of a cushion assembly according to anotherexample of the present technology positioned on a patient's face.

FIG. 19 is a top view of the cushion assembly of FIG. 18.

FIG. 20 is a front view of the cushion assembly of FIG. 18.

FIG. 2I is a bottom view of the cushion assembly of FIG. 18.

FIG. 22 is a side perspective view of the cushion assembly of FIG. 18.

FIG. 23 is a front view of a cushion assembly according to anotherexample of the present technology.

FIG. 24 is a bottom perspective view of the cushion assembly of FIG. 23.

FIG. 25 is a side perspective view of the cushion assembly of FIG. 23.

FIG. 26 is a top perspective view of the cushion assembly of FIG. 23.

FIG. 27 is a rear perspective view of the cushion assembly of FIG. 23.

FIG. 28 is a top perspective view of a cushion assembly according toanother example of the present technology.

FIG. 29 is a front view of the cushion assembly of FIG. 28.

FIG. 3O is a side perspective view of the cushion assembly of FIG. 28.

FIG. 31 is a rear perspective view of the cushion assembly of FIG. 28.

FIG. 32 is a bottom view of the cushion assembly of FIG. 28.

FIG. 33 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 33-1 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 33-2 is a cross-sectional view along the line 33-2-33-2 in FIG.33-1.

FIG. 33-3 is a cross-sectional view along the line 33-3-33-3 in FIG.33-1.

FIG. 33-4 is an enlarged detail taken from FIG. 33-2.

FIG. 34 is a cross-sectional view of the cushion assembly of FIG. 33.

FIGS. 34-37 are front perspective views of cushion assemblies havinggrip pads disposed on the textile membrane according examples of thepresent technology.

FIG. 38 is a perspective view of a patient interface according toanother example of the present technology worn by a patient.

FIG. 39 is a perspective view of a patient interface according toanother example of the present technology.

FIG. 40 is a perspective view of the patient interface of FIG. 39 wornby a patient.

FIG. 41 is a side view of the patient interface of FIG. 40.

FIG. 42 is a front perspective view of the patient interface of FIG. 40.

FIG. 43 is a front view of the cushion assembly of the patient interfaceof FIG. 39.

FIG. 44 is a top view of the cushion assembly of FIG. 39.

FIG. 45 is a bottom view of the cushion assembly of FIG. 39.

FIG. 46 is a front perspective view of the cushion assembly of FIG. 39.

FIG. 47 is a rear perspective view of the cushion assembly of FIG. 39.

FIG. 48 is a side perspective view of the cushion assembly of FIG. 39.

FIG. 49 is a front perspective view of the cushion assembly of FIG. 39showing an interior portion of the cushion assembly.

FIG. 50 is a front view of the cushion assembly of FIG. 39 showing aninterior portion of the cushion assembly.

FIG. 51 is a rear view of a cushion assembly according to an example ofthe present technology.

FIG. 52 is a front view of the cushion assembly of FIG. 51.

FIG. 53 is a cross-sectional view of the cushion assembly of FIG. 51.

FIGS. 54-56 are front perspective views of cushion assemblies havinggrip pads disposed on the textile membrane according examples of thepresent technology.

FIG. 57 is a perspective view of a patient interface 30000 according toan example of the present technology.

FIG. 58 is a perspective view of the patient interface 30000 of FIG. 57while worn by a patient.

FIG. 59 is a cross section view of the patient interface 30000 shown inFIG. 57.

FIG. 60 is a side view of the patient interface 30000 of FIG. 57 whileworn by a patient.

FIG. 61 is a front perspective view of the cushion assembly 30105 ofFIG. 57.

FIG. 62 is a rear perspective view of the cushion assembly 30105 of FIG.57.

FIG. 63 is a front view of the frame 30350 of FIG. 57.

FIG. 64 is a back view of the frame 30350 of FIG. 57.

FIG. 65 is a back view of the patient interface 30000 of FIG. 57 whileworn by a patient.

FIG. 66 is view of straps of the positioning and stabilising structure30300 of the patient interface 30000 of FIG. 57.

FIG. 67 is a perspective view of a patient interface according toanother example of the present technology worn by a patient.

FIG. 68 is a side view of the patient interface of FIG. 67.

FIG. 69 is an exploded view of the patient interface shown in FIG. 67showing the cushion assembly, frame assembly, arm covers, and elbowassembly;

FIG. 70 is a front exploded view of a cushion assembly according to anexample of the present technology.

FIG. 71 is a rear exploded view of the cushion assembly of FIG. 70.

FIG. 72 is a front view of the cushion assembly of the patient interfaceof FIG. 67.

FIG. 73 is a front perspective view of the cushion assembly of FIG. 72.

FIG. 74 is a rear perspective view of the cushion assembly of FIG. 72.

FIG. 75 is a top perspective view of the cushion assembly of FIG. 72.

FIG. 76 is a bottom perspective view of the cushion assembly of FIG. 72.

FIG. 77 is a side perspective view of the cushion assembly of FIG. 72.

FIG. 78 is a schematic illustration of a process of providing an airimpermeable layer to a textile material according to an example of thepresent technology.

FIG. 79 is a schematic illustration depicting a patient's face beingpresented to a textile membrane in light tension prior to use.

FIG. 80 is a schematic illustration showing a resulting force exerted bythe textile membrane on the patient's face due to tensile stress in thetextile membrane.

FIG. 81 is a schematic illustration of tension forces exerted on thesealing portion of a cushion assembly according to an example of thepresent technology.

FIG. 82 is a schematic illustration of a force exerted by the textilemembrane on the patient's face due to air pressure within the cavityformed by the cushion assembly.

FIG. 83 is a cutaway cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 84 is a cutaway cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 85 is a cutaway cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 86 is a cutaway cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 87 is a partial cross-sectional view of a sealing portion andsupport structure of a cushion assembly with an external seal biasingportion according to an example of the present technology.

FIG. 88 is a partial cross-sectional view of a sealing portion andsupport structure of a cushion assembly with an internal seal biasingportion according to an example of the present technology.

FIG. 89 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 90A is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 90A-1 is an enlarged view of a section of the sealing portion ofthe cushion assembly of FIG. 90A.

FIG. 90B is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 91 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 92 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 93 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 94 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 95 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 96 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 97 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 98 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 99 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 100 is a partial cross-sectional view of a cushion assemblyaccording to an example of the present technology.

FIG. 101 is cross-sectional view of a sealing portion modular assemblyaccording to an example of the present technology.

FIG. 102 is a partial cross-sectional view of a cushion assemblyincorporating the sealing portion modular assembly of FIG. 101 accordingto an example of the present technology.

FIG. 103 is a perspective view of a modular support structure accordingto an example of the present technology.

FIGS. 104 and 105 show a process of molding a sealing portion to asupporting structure according to an example of the present technology.

FIG. 106 is a side view of a sealing portion modular assembly formed bythe process illustrated in FIGS. 104 and 105.

FIGS. 107 and 108 illustrate a one size fits all cushion assemblyaccording to an example of the present technology.

FIGS. 109 and 110 illustrate a custom made cushion assembly fabricatedby utilizing a three-dimensional profile obtained by scanning apatient's face according to an example of the present technology.

FIG. 111 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 112 is a rear perspective view of the seal-forming structure of thecushion assembly of FIG. 111.

FIGS. 113 and 114 depict a knitting process.

FIG. 115 illustrates a warp knitted textile according to an example ofthe present technology.

FIG. 116 illustrates a weft knitted textile according to an example ofthe present technology.

FIG. 117 is a functional block diagram illustrating a process ofovermolding a support structure onto a textile composite to form aseal-forming structure with a textile membrane according to an exampleof the present technology.

FIG. 118A to 118C are schematic illustrations depicting a cushionassembly in use.

FIG. 119A is a perspective view of a cushion assembly according to anexample of the present technology.

FIG. 119A-1 is an enlarge detail of the seal biasing portion in FIG.119A.

FIG. 119B is a perspective view of the cushion assembly of FIG. 119Aillustrating the sealing portion being inflated in use by pressurizationof the cavity of the cushion assembly.

FIG. 120 is a bottom perspective view of a cushion assembly according toanother example of the present technology.

FIG. 121 is a bottom perspective view of a cushion assembly according toanother example of the present technology.

FIG. 122A is a top perspective view of a cushion assembly according toanother example of the present technology.

FIG. 122B is a bottom perspective view of the cushion assembly of FIG.122A.

FIG. 123A is a top perspective view of a cushion assembly according toanother example of the present technology.

FIG. 123B is a bottom perspective view of the cushion assembly of FIG.123A.

FIG. 124 is a partial perspective view of a cushion assembly accordingto another example of the present technology.

FIG. 125 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 126 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 127 is a front perspective view of a cushion assembly according toanother example of the present technology.

FIG. 128 is a rear perspective view of a cushion assembly according toanother example of the present technology.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

The following description is provided in relation to various exampleswhich may share one or more common characteristics and/or features. Itis to be understood that one or more features of any one example may becombinable with one or more features of another example or otherexamples. In addition, any single feature or combination of features inany of the examples may constitute a further example.

5.1 Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

In certain examples of the present technology, a supply of air atpositive pressure is provided to the nasal passages of the patient viaone or both nares.

In certain examples of the present technology, mouth breathing islimited, restricted or prevented.

5.2 Treatment Systems

In one form, the present technology comprises an apparatus or device fortreating a respiratory disorder. The apparatus or device may comprise anRPT device 4000 for supplying pressurised air to the patient 1000 via anair circuit 4170 to a patient interface 3000, e.g., see FIGS. 1A to 1C.

5.3 Patient Interface

A non-invasive patient interface 3000 in accordance with one aspect ofthe present technology comprises the following functional aspects: aseal-forming structure 3100, a plenum chamber 3200, a positioning andstabilising structure 3300, a vent 3400, one form of connection port3600 for connection to air circuit 4170, and a forehead support 3700. Insome forms a functional aspect may be provided by one or more physicalcomponents. In some forms, one physical component may provide one ormore functional aspects. In use the seal-forming structure 3100 isarranged to surround an entrance to the airways of the patient so as tofacilitate the supply of air at positive pressure to the airways.

If a patient interface is unable to comfortably deliver a minimum levelof positive pressure to the airways, the patient interface may beunsuitable for respiratory pressure therapy.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 6 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 10 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 20 cmH₂O with respect to ambient.

5.3.1 Plenum Chamber

The plenum chamber has a perimeter that is shaped to be complementary tothe surface contour of the face of an average person in the region wherea seal will form in use. In use, a marginal edge of the plenum chamberis positioned in close proximity to an adjacent surface of the face.Actual contact with the face is provided by the seal-forming structure.The seal-forming structure may extend in use about the entire perimeterof the plenum chamber. In some forms, the plenum chamber and theseal-forming structure are formed from a single homogeneous piece ofmaterial. In an example, the plenum chamber may be constructed from aflexible material (e.g., silicone) and may be formed as a one-piecestructure with the support structure (e.g., from any of the materialsdescribed herein as suitable for the support structure and/or plenumchamber). In an example, the seal-forming structure may be an extensionof the plenum chamber or formed as a part of the plenum chamber suchthat the plenum chamber encompasses the seal-forming structure. In suchan example, the support structure and textile membrane may be consideredpart of the plenum chamber.

5.3.2 Seal-Forming Structure

In one form of the present technology, a seal-forming structure 3100provides a target seal-forming region, and may additionally provide acushioning function. The target seal-forming region is a region on theseal-forming structure 3100 where sealing may occur. The region wheresealing actually occurs—the actual sealing surface—may change within agiven treatment session, from day to day, and from patient to patient,depending on a range of factors including for example, where the patientinterface was placed on the face, tension in the positioning andstabilising structure and the shape of a patient's face.

In one form the target seal-forming region is located on an outsidesurface of the seal-forming structure 3100.

In certain forms of the present technology, the seal-forming structure3100 is constructed from a biocompatible material, e.g. liquid siliconerubber (LSR) (or “silicone”).

A seal-forming structure 3100 in accordance with the present technologymay be constructed from a soft, flexible, resilient material such assilicone.

In certain forms, the seal-forming structure may be constructed ormolded from a single, homogeneous piece of material (e.g., liquidsilicone rubber, textile).

In some forms, such as those illustrated in FIGS. 5 to 77, theseal-forming structure has a sealing portion that comprises a textilematerial, which may covered the entirety or a portion of theseal-forming structure. In some forms, the textile may comprise amaterial formed of a network of fibres and being adapted such that it isair impermeable. For example, the textile may have an air impermeablefilm on at least one surface thereof thereby forming a textile membraneor textile sealing portion.

In some forms, the textile membrane may be constructed so as to stretchelastically in at least one dimension. For example, when a textilemembrane is constructed from a network of fibres, the textile membranemay be capable of elongating in a longitudinal warp direction and/or alateral weft direction across the textile membrane. In some forms, atextile membrane is constructed so as to elongate elastically to anextent greater than that achievable by conventional siliconeseal-forming structures.

In some forms, the textile membrane is constructed so as to besubstantially inelastic in at least one dimension. For example, when atextile membrane is constructed from a woven textile material, thetextile membrane may be capable of substantially resisting elongation ineither, or both of, a longitudinal warp direction or a lateral weftdirection across the textile membrane.

The textile membrane may comprise a single layer or a plurality oflayers. In forms where a plurality of layers is utilised, the individuallayers can be formed using the same material, or a variety of differentmaterials each with unique material properties.

In some forms, the textile membrane may comprise at least one layer thatexhibits substantially air-impermeable characteristics, whilemaintaining the material characteristics necessary for providing comfortand minimal pressure points to the patient. For example, as illustratedin FIG. 78, in some forms a textile membrane may comprise an airimpermeable material 10131 formed on an inner surface of a textilematerial 10133. The air impermeable material can in some forms belaminated onto the textile material. The air impermeable material andtextile material can in some forms be selected such that the resultingtextile membrane can exhibit a predetermined overall elasticity, or aresistance to elasticity, as required. For example, the addition of theair impermeable material (or membrane layer) may add elasticity (orstretchiness) to the textile material such that the resulting textilemembrane has increased stretchability.

In some forms, the membrane can exhibit a low spring constant (i.e. highcompliance) in both warp and weft. In such forms, unlike conventionaldesigns where a fixed cushion may cause the skin of a patient's face1300 to distort to form an effective seal, the textile material and/orthe resulting textile membrane may have a material spring constant andspring length such that the textile membrane is more compliant than thepatient's skin that engages the textile membrane. This mayadvantageously improve the comfort of the mask, and reduce the formationof localized pressure “hot spots.”

In some forms, the surface of the textile material that contacts thepatient's face 1300 can have low friction characteristics. This mayadvantageously improve the comfort of the surface texture of the textilemembrane and reduce friction relative to the patient's face 1300. Thetextile material may have a surface (e.g., herringbone) that may have afirst coefficient of friction in a first direction that is different(e.g., greater or less) than a coefficient of friction in a seconddirection. In contrast, higher friction textiles may cause the textilemembrane to grip or rub against contacted regions of the patient's face,in use. Such rubbing or gripping may cause the textile membrane to bedistorted or deformed thereby reducing the effectiveness of the seal andallowing air to leak undesirably from the device.

In some forms, the textile material of the textile membrane can have anoverall thickness of 0.275 mm or less.

In certain forms of the present technology, a system is providedcomprising more than one a seal-forming structure 3100, each beingconfigured to correspond to a different size and/or shape range. Forexample the system may comprise one form of a seal-forming structure3100 suitable for a large sized head, but not a small sized head andanother suitable for a small sized head, but not a large sized head.

It is noted that although the specification may refer (e.g., byreference character) to a particular illustrated example or a feature ofa particular illustrated example (e.g., seal-forming structure 3100),such discussion may be applicable to other examples and/or features(e.g., seal-forming structure 5100).

5.3.2.1 Sealing Mechanisms

In one form, the seal-forming structure includes a sealing flangeutilizing a pressure assisted sealing mechanism. In use, the sealingflange can readily respond to a system positive pressure in the interiorof the plenum chamber 3200 acting on its underside to urge it into tightsealing engagement with the face. The pressure assisted mechanism mayact in conjunction with elastic tension in the positioning andstabilising structure.

In one form, the seal-forming structure 3100 comprises a sealing flangeand a support flange. The sealing flange comprises a relatively thinmember with a thickness of less than about 1 mm, for example about 0.25mm to about 0.45 mm, which extends around the perimeter of the plenumchamber 3200. Support flange may be relatively thicker than the sealingflange. The support flange is disposed between the sealing flange andthe marginal edge of the plenum chamber 3200, and extends at least partof the way around the perimeter. The support flange is or includes aspring-like element and functions to support the sealing flange frombuckling in use.

In one form, a textile membrane (e.g., comprising nylon, polyester,nylon and polyester mix, microfiber or polyurethane) is used as theface-contacting portion of the seal-forming structure 3100 for the CPAPmask. The textile membrane may have properties such that it is capableof elongating in at least one dimension. The textile membrane can beheld under a tension force across the support structure prior to and/orduring use. Prior to use, the textile membrane can be either permanentlyattached (e.g., molded) or attached as a removable module to the supportstructure in such a way that it is pre-tensioned and lightly stretched.

Alternatively, the textile can be formed as a complex three-dimensionalpre-determined shape such that it is untensioned (e.g., loose, slackand/or unwrinkled) prior to and/or during use, but there are nosubstantial leak causing wrinkles. Due to manufacturing, the textilepolymers can shrink such that the inherent pre-tension in the textilemembrane is lost however the textile membrane may remain substantiallywrinkle free.

FIG. 79 illustrates an example wherein the textile membrane has a lighttension in both the X and Y directions through the textile surface.Before the patient's face 1300 (such as a nose) approaches and depressesthe textile membrane 3130, the textile membrane is adapted to form aconstant surface without interruptions such as creases, folds orwrinkles in the textile material prior to the contact between thepatient's face 1300 and the seal-forming structure 3100. In some forms,this can be accomplished by the application of the light pre-tension, orby moulding the textile membrane such that it is substantially free ofany leak causing wrinkles. This can be advantageous in ensuring that thetextile membrane forms a smooth and continuous seal on and around thepatient's face 1300. This may provide improved respiratory pressuretherapy by reducing occurrences of folded or wrinkled sections of theseal-forming structure 3100 through which treatment air may leak. Thiscan also be advantageous in ensuring the textile membrane remains undera minimum threshold of tension as it is forced against the patient'sface 1300 (FIG. 80).

In some forms, regions of the textile membrane can be pre-tensioned andlightly stretched while other regions of the textile membrane can remainslack. For example, in some forms the subnasal region can bepre-tensioned whilst the region that cups the outer sides of thenostrils and/or the patient's mouth could remain tension-free (e.g.,with excess material) so as to form a saddle region or valley shapeprior to use. This may advantageously improve the seal efficiency whilereducing pressure (i.e. “hot spots”) on regions where the facialanthropometrics protrude a greater distance into or towards the cavity.In another example, the side of nose region and/or the nasal bridgeregion may remain untensioned and/or slack prior to use, in order toprovide additional material to accommodate the facial contours of thesesensitive facial areas. In another example a bridge portion (e.g.,bridge portion 3104) extending between two naris openings may beuntensioned, slack and/or buckled with excess material prior to use, asshown for example in FIG. 33-1. A bridge portion (e.g., 3104) withexcess material may allow the textile membrane to expand (e.g., in thesuperior-inferior (height) direction to accommodate different sizenoses.

In some forms, instead of having a region that is pre-tensioned, thetextile membrane may be formed to be substantially free of leak causingwrinkles. This may be advantageous as it may be difficult to formsubstantially leak free complex three-dimensional shapes from a slacktextile membrane, or from a textile membrane that is provided withexcess non-tensioned material. The untensioned textile membrane may bemore comfortable is some arrangements as it may apply less pressure onthe patient's face.

In some forms, the textile membrane may be in a substantiallytension-free state and formed onto the support structure or directlyonto the plenum chamber in such a manner so as to remain untensionedand/or slack. In an example, such a textile membrane may still maintainan unwrinkled state so as to avoid leaks in the seal with the patient'sface. An untensioned and/or unwrinkled textile membrane may in someforms utilise a cushion support (e.g., underlying cushion, seal supportregion (e.g., support structure) and/or air pressure within the cavityto enable an effective seal to be formed with a patient's face.

In some forms, the tensioned and/or unwrinkled state (see FIGS. 80 and81) in the textile membrane may be maintained so as to maintain sealingcontact with the patient's face 1300 by one or a combination of thefollowing:

-   -   a) the pre-applied tensile stress of the textile membrane and        the additional applied tensile stress as the patient's face 1300        engages the textile membrane;    -   b) the pre-formed state of the textile membrane formed as a        non-tensioned, yet substantially constant surface, without leak        causing interruptions such as creases, folds, buckles or        wrinkles in the textile membrane.    -   c) the rigidity of the support structure and/or plenum chamber,        and the ability of the support structure and/or plenum chamber        to accommodate and react to the applied tensile stress as the        patient's face 1300 engages the textile membrane; and    -   d) the additional applied loading of the air pressure from        within the cavity against the inner surface of the textile        membrane. The interior air pressure can apply additional tensile        stress against the interior surface of the textile membrane so        as to further stretch and stress the textile membrane against        the patient's face 1300 (e.g., creating a pressure-assisted        seal).

By retaining the textile membrane under tensile stress and/or in aunwrinkled state continuously prior to and during use, the textilemembrane can conform to the patient's facial profile while minimizingwrinkles and/or blow-out of the seal-forming structure. In some forms,this may also improve seal performance by maximising the contact area ofthe textile membrane on the patient's face 1300. In some forms, this mayalso improve the performance of the CPAP device when it is impacted byexternal lateral or longitudinal forces (e.g., tube drag).

In some forms, when the plenum chamber is pulled a small distance awayfrom the patient's face 1300, the applied loading of the air pressurefrom within the plenum chamber can assist the textile membrane inretaining an effective seal. The applied loading of the air pressure canbe sufficient so as to elastically stretch the textile membrane in atleast one dimension such that it forms a “hover-craft” like ballooneffect over the anthropometric contours of a patient's face 1300 thusretaining an effective seal thereon.

In some forms, the textile membrane may be held under tension by arelatively stiffer support structure. In various forms, the supportstructure can be formed from for example, any of silicone, PU foam, PUsolid material or another suitable materials. In some forms, the supportstructure may be relatively less stiff than a shell or frame of theplenum chamber.

In some forms, the magnitude of the tensile stress can vary across thetextile membrane of the seal-forming structure as required. For example,there may be a region of stress concentration proximal to one or moreholes in the textile membrane through which treatment is administered orin wider stretches of material.

In some forms, the seal-forming structure can utilize a number ofdifferent cushion configurations including a single air assisted textilemembrane, a double air assisted textile membrane, a textile membranewith compression support, or a textile membrane with TPU/TPE/Si support.In some forms, the cushion configuration of the seal-forming structuremay be formed such that it can advantageously provide a“one-size-fits-most” solution.

In examples, the seal-forming structure and plenum chamber can beapplied to nasal cushions, nasal cradles, oronasal cushions,ultra-compact full-face masks, full-face masks and other suitablecushion arrangements.

In some forms, the textile membrane may be configured to generate aneffective seal across the patient's pronasale, as shown for example inFIG. 58. In some forms, the textile membrane may be configured togenerate an effective seal against the subnasale portion of the patientsnose such that the textile membrane does not engage the pronasale, asshown for example in FIG. 40.

In some forms, the stretching and/or maintenance of an unwrinkled stateof the textile membrane so as to conform to the patient's face 1300, inuse, may apply stress on the walls of the support structure. This stresscan pull the walls of the support structure inwardly towards one anotherin use. In some forms, the support structure may be adapted to resistthe applied stress load so as to prevent an inward deformation. Thus,the rigidity of the support structure may apply further stress to thetextile membrane which in turn may cause elastic stretching of thetextile membrane, in use.

In some forms, such as illustrated in FIGS. 87 and 88, the supportstructure may include a pleat or fold (e.g., seal biasing portions10140, 10140′) that utilizes the internal air pressure to dynamicallysupport the textile membrane. This may advantageously provide furthersupport to the textile membrane when under dynamic loads (e.g. tubedrags). In other forms, the pleat or fold may utilise internal airpressure to decouple dynamic loads (e.g. tube drags) from the sealforming structure. In some forms, the air pressure within the cavity mayapply a load against the inside surface of the textile membrane tocreate further tensile stress such that the textile membranesubstantially fills the depressed contours of a patient's face 1300(e.g. around the sides of the nose). In some forms, the elasticity ofthe textile membrane, when combined with the applied load of theinternal air pressure, can elastically stretch the textile membrane suchthat it forms a larger seal contact area on the patient's face. This mayin some forms also be advantageous in providing a continuous seal, evenwhen the mask is partially displaced from an optimal interface with thepatient's face, as the textile membrane may partially inflate (i.e. a“hovercraft effect”) due to the counter-force from the internal airpressure.

In some forms, such as illustrated in FIGS. 35-37 and 54-56, the textilemembrane may have one or more grip pads 29150, 31150 arranged thereon.In an example, the grip pads 29150, 31150 may be configured to be eithersubstantially flat along the patient facing surface of the textilemembrane. In other examples, the grip pads 29150, 31150 may be embossedsuch that the grip pad may form a bead or rim that protrudes slightlyabove the surface of the textile membrane. In some forms, the grip pads29150, 31150 may have a high coefficient of friction. In some forms, thegrip pads may have a determined shape (e.g., ovular (see FIGS. 35, 37,54, and 56), circular, square, etc.). In some forms, the grip pads maybe elongate (see FIGS. 35 and 54). In some forms, the grip pads 29150,31150 may be linear. In some forms, the grip pads may be arranged in apattern across the surface of the seal-forming structure 3100. In someforms, the grip pads may be arranged sporadically across the surface ofthe seal-forming structure 3100 (see FIGS. 37 and 56). In some forms,the grip pads may be arranged to form a perimeter proximal to theperipheral edges of the textile membrane (see FIGS. 34, 35, 54 and 55).In some forms, the grip pads 29150, 31150 that form a perimeter can bein the form of a dotted line (see FIGS. 35 and 54). In some forms, thegrip pads that form a perimeter can be in the form of a solid line (seeFIGS. 36 and 55). In some forms, the grip pads that form a perimeter canbe in the form of a plurality of lines, dotted or solid or a combinationthereof. In some forms, the grip may assist a textile membrane ingripping a patient's face. In an example, the grip pads are formed as arelatively thin layer of silicone applied to the surface of the textilemembrane.

In some forms, the textile membrane may be integrated to the supportstructure by attaching (e.g., molding) an outer edge (e.g., outerperimeter) of the textile membrane around a lip of the curved edges(i.e., inner edge) of the support structure. In an example, the textilemembrane may be slightly angled “inwardly” toward the mask interior. Inan example, the textile membrane is attached so as to provide a frontface of the seal-forming structure. That is, the support structure formsthe portion of the seal-forming structure that curves from an anteriorside of the seal-forming structure to the posterior face-contacting side(see FIG. 11). In this way, the textile membrane can avoid havingportions that curve around from the posterior side to the anterior side.By this arrangement, the textile membrane may be presented only along afront face of the seal-forming structure, as shown for example in FIGS.11-17). This arrangement may be advantageous since the textile membranemay not need to be folded or cut to blend around the corners of thesupport structure. This may be beneficial in reducing the occurrence ofprotruding folds or wrinkles in the textile membrane (which may causeleakage) thereby improving the performance of the seal.

In some forms, the textile membrane may be attached to an outer edge ofthe textile membrane such that the textile membrane forms part of theportion of the seal-forming structure that curves from the anterior sideof the seal-forming structure to the posterior face-contacting side (seeFIGS. 33-1 to 33-4, 73 and 74 for example). This may present more of thetextile membrane surface (as opposed to the support structure) forengagement with the patient's face, which may improve comfort. In anexample, the textile membrane is attached to the support structure by aspecific process (as will be described later) that may form the curvedportions without creating folds, creases, wrinkles, or buckles in thetextile membrane surface. As can be seen, in some examples, at atransition portion 36, the support structure and the textile membranemay both have a radius of curvature (e.g., the same or similar radius ofcurvature) along the curve 35 in a direction from the anterior side ofthe seal-forming structure to the posterior side of the seal-formingstructure (see FIGS. 33-1 to 33-4). The textile membrane may have apredefined curvature imparted thereto such that a portion of the textilemembrane not directly supported by the support structure extends alongthe curve 35 (FIGS. 33-2 to 33-4). This may help create a dome shape(e.g., convex dome) in certain regions (e.g., lateral side 3250 and/orcorner regions 3252) of the textile membrane which may help the textilemembrane seal against the contours of the patient's face (e.g., thesubalare region of the patient's face (i.e., the corner of nose regions,i.e., the region where the ala terminate at the lip superior proximatethe nasolabial sulcus)), as shown for example in FIG. 33-1. The domeshape may help prevent creases, wrinkles, folds, and buckles fromforming in the textile membrane which may help avoid the creation ofleak paths. Also, the dome shape may help the textile reach into hard toseal areas of the patient's face, such as the corner of nose regions.The textile membrane 29130 may have a saddle shape at a medial subnasaleregion 3260 configured to seal against the patient's subnasale therebymatching the saddle shape formed by the patient's nasolabial angle andlip superior, as shown in FIG. 33-1. Similarly, a pronasale region 3270may also have a saddle shape configured to seal against the matchingprofile presented at or below the patient's pronasale. The curvature(e.g., magnitude of curvature and/or radius of curvature) of the textilemembrane in the direction of the curve 35 may vary in different regionsof the cushion assembly along an outer perimeter of the textilemembrane. For example, as shown in FIG. 33-2, the textile membrane 29130in the medial pronasale region 3270 may have different curvature in thedirection of the curve 35 than the textile membrane in the medialsubnasale region 3260. In the FIG. 33-2 example, the textile membrane inthe medial pronasale region 3270 may a relatively larger (e.g., smallerradius) curvature (e.g., negative curvature in an inferior-superiordirection along curve 35) than the curvature (e.g., negative curvaturein an inferior-superior direction along curve 35) in the medialsubnasale region 3260. In an example, the curvature (e.g., magnitude ofcurvature and/or radius of curvature) at a lateral side 3250 of thetextile membrane may be different that the curvature at the medialpronasale region 3270 and/or medial subnasale region 3260. The nasalportion of the cushion assemblies 14105, 30105, 31105, as shown forexample in FIGS. 43, 52 and 61, may have similar dome and saddle shapefeatures.

In the FIG. 73 example, the curvature of the textile membrane 16230 fromthe connection with the support structure 16220 (e.g., at the transitionportion) may continue to the inner edge of the textile membrane. Forexample, the textile membrane may have a dome shape or saddle shape atthe inner edge of the textile membrane in certain regions of thecushion.

In some forms, the textile membrane may be slightly angled or curvedinwardly toward the mask interior (e.g., positive curvature in aleft-right direction), as shown for example in FIGS. 11-17, 23-26 and3-37. In some forms, the textile membrane may form a dome shape over thesupport structure, as shown for example in FIGS. 19-22 and 43-50. It isnoted that any of the cushion assemblies disclosed herein may have thetextile membrane attached to an outer edge of the textile membrane suchthat the textile membrane forms part of the portion of the seal-formingstructure that extends along the curve 35 from the anterior side of theseal-forming structure to the posterior face-contacting side asdiscussed above with reference to FIG. 33-1, such that, for example, thetextile membrane 6130 of cushion assembly 6105 may have more of a domeshape by virtue of a more convex shape from one lateral side to theother lateral side.

In some forms where the textile membrane is not under continuous tension(prior to and/or during use) or is non-elastic, the textile membrane mayform an improved air-assisted seal on a patient's face that conformsdynamically to alterations/movement (i.e. “hovercraft effect”), forexample due to the textile membrane being thinner and having a lowerstructural stiffness than silicone membrane.

In some forms, the textile membrane may be supported by a secondary ortertiary support structure that may act as a cushion support or may actas a biasing mechanism that is pressure assisted and that aids insealing at the patient's face. A cushion support can provide additionalflexibility and may be suitable for use by most patient's faces(one-size-fits-most). The second or third support layer can be formedusing a membrane of a textile, a textile with PU/Si membrane, laminatedopen cell foam, a laminated PU foam, PU molding, TPU/TPE or silicone. Insome forms, additional support layers can themselves be supported by astructural/rigid plastic such as PP/PC/PA/PET or other suitablematerials.

In some forms, 3D printing of the textile membrane and/or cushionsupport sections as a “skeleton” can reduce the thickness and as aconsequence, may reduce the weight of the mask.

In some forms, multiple different layers of the mask layers could beprinted with different rigidity, hardness, or thicknesses. For example,“skeleton” sections may be formed using Si, PU Foam, PU solid materialor any suitable plastic material.

In some forms, a pleat or fold section can be formed along a cushionassembly (e.g., in the textile membrane and/or the support structure)that may provide a dynamic force/support or decoupling region.

In one form, the seal-forming structure may comprise a compressionsealing portion or a gasket sealing portion. In use the compressionsealing portion, or the gasket sealing portion is constructed andarranged to be in compression, e.g. as a result of elastic tension inthe positioning and stabilising structure.

In one form, the seal-forming structure may comprise a biasing mechanismto assist in sealing between the textile contacting portion (sealingportion) of the seal forming structure and the patient's face.

In one form, the seal-forming structure comprises a tension portion. Inuse, the tension portion is held in tension, e.g. by adjacent regions ofthe sealing flange.

In one form, the seal-forming structure comprises a region having atacky or adhesive surface.

In certain forms of the present technology, a seal-forming structure maycomprise one or more of a pressure-assisted sealing flange, acompression sealing portion, a gasket sealing portion, a tensionportion, and a portion having a tacky or adhesive surface.

5.3.2.2 Nose Bridge or Nose Ridge Region

In one form, the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on a nose bridge regionor on a nose-ridge region of the patient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on a nose bridge region or on anose-ridge region of the patient's face.

5.3.2.3 Upper Lip Region

In one form, the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on an upper lip region(that is, the lip superior) of the patient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on an upper lip region of thepatient's face.

5.3.2.4 Chin-Region

In one form the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on a chin-region of thepatient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on a chin-region of the patient'sface.

5.3.2.5 Forehead Region

In one form, the seal-forming structure forms a seal in use on aforehead region of the patient's face. In such a form, the plenumchamber may cover the eyes in use.

5.3.2.6 Nasal Pillows

In one form the seal-forming structure of the non-invasive patientinterface 3000 comprises a pair of nasal puffs, or nasal pillows, eachnasal puff or nasal pillow being constructed and arranged to form a sealwith a respective naris of the nose of a patient.

Nasal pillows in accordance with an aspect of the present technologyinclude: a frusto-cone, at least a portion of which forms a seal on anunderside of the patient's nose, a stalk, a flexible region on theunderside of the frusto-cone and connecting the frusto-cone to thestalk. In addition, the structure to which the nasal pillow of thepresent technology is connected includes a flexible region adjacent thebase of the stalk. The flexible regions can act in concert to facilitatea universal joint structure that is accommodating of relative movementboth displacement and angular of the frusto-cone and the structure towhich the nasal pillow is connected. For example, the frusto-cone may beaxially displaced towards the structure to which the stalk is connected.

5.3.3 Nasal Cushion

Referring to FIGS. 5-14, a patient interface 3000, 6000 with a cushionassembly 3105 including a seal-forming structure 3100 and a plenumchamber 3200 is shown in accordance with a first example of the presenttechnology. FIGS. 15-17 show a cushion assembly 5105 including aseal-forming structure 5100 and a plenum chamber 3200 in accordance witha second example of the present technology. FIGS. 18-22 show a cushionassembly 6105 including a seal-forming structure 6100 and a plenumchamber 3200 in accordance with a third example of the presenttechnology. FIGS. 23-27 show a cushion assembly 7105 including aseal-forming structure 7100 and a plenum chamber 3200 in accordance witha fourth example of the present technology. Referring to FIGS. 28-32 acushion assembly 8105 including a seal-forming structure 8100 and aplenum chamber 3200 is shown in accordance with a fifth example of thepresent technology. FIG. 3 shows a patient interface 9000 with a cushionassembly 9105 including a seal-forming structure 9100 and frame 9200 inaccordance with a sixth example of the present technology.

FIGS. 11-14 include broken lines demarcating regions of differentthickness, and it should be understood that these are only nominalboundaries, not actual structures.

The examples of seal-forming structures 3100, 5100, 6100, 7100, 8100,9100 described in the preceding paragraphs may be considered nasalcradle cushions and are intended to provide a flow of pressurised gas tothe patient's nares by sealing against at least the underside of thepatient's nose. The exemplary seal-forming structures may engage thepatient's face below the bridge of the nose and some examples, dependingon the size and shape of the patient's nose, may engage the patient'snose below the pronasale. The exemplary seal-forming structures may alsoengage the patient's face at least above the upper vermillion. Thus, theexemplary seal-forming structures may seal against the patient's lipsuperior in use. Furthermore, the patient's mouth may remain uncoveredby the seal-forming structures of the depicted examples such that thepatient may breathe freely, i.e., directly to atmosphere, withoutinterference from the seal-forming structure. The under-the-nose nasalcradles may be configured such that they do not have an aperture sizedto receive the patient's nose within the cavity. Further, a height ofthe cushion from an inferior edge of the textile membrane at a medialsubnasale region to a superior edge of the textile membrane at a medialpronasale region may be less than a width of the cushion in a left-rightdirection from a lateral edge of the textile membrane to the otherlateral edge of the textile membrane (see FIGS. 33 and 33-1 forexample).

Examples of a nasal cradle cushion, e.g., the exemplary seal-formingstructures disclosed herein, may include a superior saddle or concaveregion that has positive curvature across the cushion. Also, a nasalcradle cushion may be understood to have a single target seal formingregion or surface, whereas a pillows cushion may have two target sealforming regions (one for each naris). Cradle cushions may also have aposterior wall that contacts the patient's lip superior and an upper,central, surface contacts the underside of the patient's nose. These twosurfaces on the patient's face may form a nasolabial angle between them(see FIG. 2E). A cradle cushion may be shaped to have a nasolabial anglewithin the range of 90 degrees to 120 degrees.

Furthermore, the exemplary seal-forming structures may also be shapedand dimensioned such that no portion of the seal-forming structureenters into the patient's nares during use.

Plenum Chamber

Referring to FIGS. 5-17, the plenum chamber 3200 has a perimeter that isshaped to be complementary to the surface contour of the face of anaverage person in the region where a seal will form in use. In use, amarginal edge of the plenum chamber 3200 is positioned in closeproximity to an adjacent surface of the face. Actual contact with theface is provided by the seal-forming structure 3100. The seal-formingstructure 3100 may extend in use about the entire perimeter of theplenum chamber 3200.

In certain forms of the present technology, the plenum chamber 3200 isconstructed from a relatively rigid material (e.g., polycarbonate) ascompared to the seal-forming structure. Alternatively, the plenumchamber 3200 may be constructed from a flexible material (e.g.,silicone) and may be formed as a one-piece structure with the supportstructure (e.g., from any of the materials described herein as suitablefor the support structure and/or plenum chamber). In an example, theseal-forming structure may be an extension of the plenum chamber orformed as a part of the plenum chamber such that the plenum chamberencompasses the seal-forming structure. In such an example, the supportstructure and textile membrane may be considered part of the plenumchamber. In another example, the plenum chamber 3200 may be constructedfrom a transparent material, e.g. a transparent polycarbonate. The useof a transparent material can reduce the obtrusiveness of the patientinterface, and help improve compliance with therapy. The use of atransparent material can aid a clinician to observe how the patientinterface is located and functioning.

In certain forms of the present technology, the plenum chamber 3200 isconstructed from a translucent material. The use of a translucentmaterial can reduce the obtrusiveness of the patient interface, and helpimprove compliance with therapy.

FIGS. 5 and 10-17 show examples of the seal-forming structure 3100 withthe plenum chamber 3200. The seal-forming structure 3100 may include aplenum chamber connection opening where the seal-forming structure 3100is sealingly joined to the plenum chamber 3200. The seal-formingstructure 3100 and the plenum chamber 3200 may at least partly form acavity 3101 that is pressurized by the flow of air. In the illustratedexample, the seal-forming structure 3100 and the plenum chamber 3200together form the cavity 3101.

The connection between the seal-forming structure 3100 and the plenumchamber 3200 at the plenum chamber connection opening 3106 may be apermanent bond. The connection between the seal-forming structure 3100and the plenum chamber 3200 at the plenum chamber connection opening3106 may be a chemical bond. The seal-forming structure 3100 may bejoined to the plenum chamber 3200 at the plenum chamber connectionopening without a mechanical connection. Alternatively, the seal-formingstructure 3100 may be joined to the plenum chamber 3200 at the plenumchamber connection opening by a mechanical removably detachableconnection.

At each lateral side of the plenum chamber 3200 there may be a plenumchamber lateral end 3202 in the form of a hollow passageway forming aplenum chamber inlet port sized and structured to receive a flow of air.A plenum chamber connector 3204 may also be provided at each lateralside of the plenum chamber 3200 laterally outward of the plenum chamberlateral end 3202. The plenum chamber connectors 3204 may connect torespective ends 3314 of the positioning and stabilising structure 3300.The connection between the plenum chamber connectors 3204 and respectiveends 3314 of the positioning and stabilising structure 3300 may bereleasable at both sides. In other examples, one side may have apermanent connection while the other side has a releasable connection.In still further examples, both connections between the plenum chamberconnectors 3204 and respective ends 3314 of the positioning andstabilising structure 3300 may be permanent.

The plenum chamber lateral ends 3202 may receive the flow of pressurisedgas from the positioning and stabilising structure 3300. The flow ofpressurised gas may then pass through the plenum chamber 3200, thenthrough the seal-forming structure 3100, and into the patient's airwaysfor inhalation.

The ends 3314 of the positioning and stabilising structure 3300 may beconnected to the plenum chamber lateral ends 3202. Each plenum chamberconnector 3204 in these examples may include a slot 3209, a chamferededge 3208, and a notch 3206 that may be removably connected to a clip ofthe positioning and stabilizing structure with a snap-fit.

The plenum chambers 3200 shown in FIGS. 18-32 according to the third,fourth and fifth examples of the present technology may be similar oridentical to the plenum chamber of FIGS. 10-17. It should also beappreciated that one or more aspects of the present technology may becombinable with one or more aspects of: U.S. Provisional Application No.62/764,992, filed Aug. 20, 2018 and entitled “Patient Interface” orPCT/AU2019/050873, filed Aug. 20, 2019, each of which is herebyincorporated herein by reference in its entirety. For instance, theplenum chamber of the present technology may be identical to the plenumchamber in any of the embodiments of the '992 or '837 application.Additionally, the seal-forming structures disclosed herein may replaceany of the seal-forming structures in any of the patient interfacesdisclosed in the '992 or '873 application, and the seal-formingstructures of the present technology may include any of the features ofthe seal-forming structures in any of the embodiments of the '992 or'873 application.

In the example of FIGS. 28-32, the plenum chamber 13200 has a plenumchamber lateral end 3202, plenum chamber connector 3204, notch 3206,chamfered edge 3208, and slot 3209 similar to the plenum chamber 3200described above. However, the vent 3400 may be provided by a vent insert13400 that attaches, removably or permanently, to the plenum chamber13200 (e.g., by insertion into an opening in the plenum chamber). It isnoted that any of the other examples may have a vent insert (e.g., thevent 3400 in plenum chamber 3200 of FIGS. 10-27 may be provided by avent insert 13400 such as shown in FIGS. 28-32).

In the example of FIG. 38, the frame 9200 may include a centrallylocated connection for an air circuit 4170. The frame may also includeheadgear attachment portions 9210 at lateral sides thereof. Theseal-forming structure 9100 may be connected to the frame 9200 byspaced-apart connectors 9122, which may include a clip on theseal-forming structure and a receiving connector on the frame.

Seal-Forming Structure of the Present Technology

The seal-forming structures 3100, 5100, 6100, 7100, 8100, 9100, 29100may each include a support structure 3120, 6120, 7120, 8120, 9120, 29120that provides support to a sealing portion 3130, 5130, 6130, 7130, 8130,9130, 29130 (e.g., a textile membrane). The sealing portion isconfigured to sealingly engage the patient's face. Also, depending onthe size and contours of the patient's nose, in the examples of FIGS.5-27, the support structure may also sealingly engage the patient'sface.

The exemplary seal-forming structures 3100, 5100, 6100, 7100, 8100,9100, 29100 while different in various aspects to be described furtherbelow, may each include a support structure having at least two regions(e.g., two, three or four regions) of different thickness (e.g.,seal-forming structure 3100 comprises support structure 3120 which has awall structure having lateral support regions 3122 of an increasedthickness with respect to other portions of the wall structure). Forexample, as shown in FIG. 59, portions (d1) of the support structure maybe thicker than portions (d2) of the support structure. For example,portions (d1) may be adjacent to or connecting to the plenum chamber andportions (d2) may be adjacent to or connecting to the sealing portion soas to provide structural stability at the connection with the plenumchamber and flexibility at the interface with the patient.Alternatively, the thicker lateral support regions 3122 may be located,for example, at the corner of nose region of the seal-forming structure(and e.g., may connect directly to the textile membrane), to ensureadequate sealing in the subalare region of the patient's face.

Further, in the depicted examples, each sealing portion has two separatenaris openings 3102 corresponding respectively to one of the patient'snares to provide the flow of air to both of the patient's nares. Theremay also be a bridge portion 3104 positioned between the naris openings3102. The bridge portion 3104 may assist in providing a taut textilemembrane prior to and/or during use. In an alternative example, a singlehole may be used to provide the flow of air to both of the patient'snares.

The seal-forming structure 3100, as described above, may include aplenum chamber connection opening where the seal-forming structure 3100is sealingly joined to the plenum chamber 3200. In the examples of FIGS.5-38, the support structure 3120, 5120, 6120, 7120, 8120, 9120, 29120 isconnected directly to the plenum chamber or frame. Thus, the supportstructure may include an opening where the support structure issealingly joined to the plenum chamber 3200.

The support structure may be less rigid than the plenum chamber 3200 andmay be constructed from silicone, foam (e.g., polyurethane foam) (seeFIGS. 28-32), polyurethane solid material, thermoplastic elastomers(e.g., thermoplastic polyurethane), suitable plastics, or other suitablematerials, as will be described later. Further, the sealing portion maybe less rigid than the support structure and may be constructed from atextile material such as nylon, polyester, nylon and polyester mix,microfiber or polyurethane, for example, as will be described in moredetail later. The sealing portion described in any of the examples ofthis disclosure may be referred to as a textile sealing portion ortextile membrane and may comprise a textile material having an airimpermeable material layered, coated or otherwise applied thereon.

The support structure may have an aperture formed therein providing aninner edge of the support structure along which the sealing portion(e.g., an outer perimeter of the sealing portion) may be attached to thesupport structure such that the sealing portion extends radiallyinwardly of the seal-forming structure beyond or to a further extentthan the support structure, as shown for example in FIGS. 11-27 and33-38. For example, the sealing portion may be molded around the inneredge of the support structure or connected to the support structure inother suitable ways, as will be described later. However, in thealternative example of FIGS. 28-32, the sealing portion 8130 may belayered onto the support structure 8120 (e.g., foam).

Referring to FIGS. 11-14, the seal-forming portion 3100 has a wallstructure that may include lateral support regions 3122 having anincreased thickness as compared to other portions of the wall structureof the support structure 3120. At each lateralmost side of theseal-forming structure 3100, a lateral support region 3122 may beprovided. The seal-forming structure 3100 may include two lateralsupport regions 3122, each spaced distal from a plane bisecting theseal-forming structure 3100 that would be parallel to the patient'ssagittal plane in use. The lateral support regions 3122 may be thethickest portions of the seal-forming structure 3100 to provideresistance to lateral displacement, e.g., caused by the patient sleepingon the side of their head such that the pillow pushes laterally againstthe seal-forming structure, and to provide robust engagement against thepatient's ala. The lateral support regions 3122 may have a thickness ofapproximately 0.9 mm to approximately 1.5 mm, or approximately 1.3 mm toapproximately 1.4 mm, or approximately 1.3 mm, or approximately 1 mm toapproximately 1.5 mm. Due to the lateral support regions 3122 being thethickest regions of the seal-forming structure 3100 in the depictedexamples, the lateral support regions 3122 may also provide the greatestresistance to deformation.

Additionally, the lateral support regions 3122 may provide sufficientrigidity to ensure adequate sealing (e.g., by the lateral supportregions 3122) in the subalare region of the patient's face (i.e., theregion where the ala terminate at the lip superior proximate thenasolabial sulcus), which is a region of particularly complex geometry.The subalare region of a patient's face presents particularly complexgeometry because at least three facial surfaces—the ala, the lipsuperior, and the cheek-converge at this region. Thus, sufficientstiffness in the lateral support regions 3122 may ensure that theseal-forming structure 3100 can be urged into the subalare region bytension forces from the positioning and stabilising structure 3300without collapsing. The lateral support regions 3122 may lie on thepatient's face in a region inferior to the ala of the patient's nose aswell as inferior and laterally outwards of the patient's nose, forexample, between the nasolabial sulcus and the regions of the lipsuperior located inferior to the ala.

The seal-forming structure 5100 in the example of FIGS. 15-17 may have asealing portion 5130 that is expanded as compared to the sealing portion3130 in FIGS. 11-14. That is, the support structure 5120 is reduced andthe sealing portion 5130 is expanded in the seal-forming structure 5100such that the sealing portion 5130 may be configured to engage thesubalare region of the patient's face in use. As a result, theseal-forming structure 5100 may be more flexible and compliant so as tomore readily conform to the patient's facial contours.

Turning to FIGS. 18-22, the seal-forming structure in this example isarranged to provide a larger cavity 3101 such that the sealing portion6130 protrudes further from the plenum chamber in a direction towardsthe patient's face in use by creating more tension in the sealingportion thereby causing the sealing portion to balloon outwards. In use,the patient's nose is able to press against the sealing portion 6130 inthe direction towards the cavity 3101 and the plenum chamber 3200causing the sealing portion 6130 to stretch and invert such that spacecreated by the cavity 3101 receives the patient's nose thereby allowingthe sealing portion 6130 to seal above the patient's pronasale, as shownin FIG. 18. In contrast, the sealing portions 3130, 5130 seal below thepatient's pronasale, as shown in FIG. 10.

The sealing portion 7130 in the example of FIGS. 23-27 is alsoconfigured to seal above the patient's pronasale due to the height ofthe cushion. The sealing portion 7130 is configured to seal further inthe direction of the sellion along the ridge of the nose as compared tothe sealing portion 6130.

In the example cushion assembly of FIGS. 28-32, the support structure8120 may be provided by a foam material layered onto the plenum chamber3200. The sealing portion 8130 may be layered directly onto the supportstructure. The support structure 8120 may extend across the plenumchamber connection opening except for a pair of holes formed thereincorresponding to the naris opening 3102 in the sealing portion 8130.This arrangement may provide a compression type seal against thepatient's face wherein the cushion assembly 8105 is pulled towards thepatient's face by headgear causing the seal-forming structure 8100 toconform to the patient's facial contours through compression of thesupport structure 8120.

The cushion assembly 8105 is configured to seal against an underside ofthe patient' nose. The seal-forming structure 8100 includes an endportion 8122 that curves around a posterior portion of the plenumchamber 3200 and is configured to engage the patient's lip superior inuse.

Referring to FIGS. 33-37, cushion assembly 29105 is similar to cushionassembly 3105, but may extend further in a lateral left-right direction.Cushion assembly 29105 includes seal-forming structure 29100, supportstructure 29120 and sealing portion 29130. Referring to FIG. 33-1,cushion assembly 29105-1 is similar to cushion assembly 29105, but mayhave a textile membrane 29105 formed such that the textile membraneforms part of the portion of the seal-forming structure that curves fromthe anterior side of the seal-forming structure to the posteriorface-contacting side, as described earlier.

As described earlier, FIGS. 35-37 show grip pads 29150 on the surface ofthe textile membrane.

In the FIG. 38 example, the sealing portion 9130 is arranged to sealabove the patient's pronasale.

5.3.3.1 Positioning and Stabilising Structure

The cushion assembly 3105, 5105, 6105, 7105, 8105, 29105 of the patientinterface 3000, 6000 of the present technology may be held in sealingposition in use by the positioning and stabilising structure 3300. Thecushion assembly 9105 of the patient interface 9000 may be held insealing position in use by the positioning and stabilising structure9300.

In one form the positioning and stabilising structure 3300, 9300provides a retention force at least sufficient to overcome the effect ofthe positive pressure in the cavity 3101 to lift off the face.

In one form the positioning and stabilising structure provides aretention force to overcome the effect of the gravitational force on thepatient interface.

In one form the positioning and stabilising structure provides aretention force as a safety margin to overcome the potential effect ofdisrupting forces on the patient interface, such as from tube drag, oraccidental interference with the patient interface.

In one form of the present technology, a positioning and stabilisingstructure 3300, 9300 is provided that is configured in a mannerconsistent with being worn by a patient while sleeping. In one examplethe positioning and stabilising structure has a low profile, orcross-sectional thickness, to reduce the perceived or actual bulk of theapparatus. In one example, the positioning and stabilising structurecomprises at least one strap having a rectangular cross-section. In oneexample the positioning and stabilising structure comprises at least oneflat strap.

In one form of the present technology, a positioning and stabilisingstructure is provided that is configured so as not to be too large andbulky to prevent the patient from lying in a supine sleeping positionwith a back region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure is provided that is configured so as not to be too large andbulky to prevent the patient from lying in a side sleeping position witha side region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure 3300, 9300 is provided with a decoupling portion locatedbetween an anterior portion of the positioning and stabilisingstructure, and a posterior portion of the positioning and stabilisingstructure. The decoupling portion does not resist compression and maybe, e.g. a flexible or floppy strap. The decoupling portion isconstructed and arranged so that when the patient lies with their headon a pillow, the presence of the decoupling portion prevents a force onthe posterior portion from being transmitted along the positioning andstabilising structure and disrupting the seal.

In one form of the present technology, a positioning and stabilisingstructure comprises a strap constructed from a laminate of a fabricpatient-contacting layer, a foam inner layer and a fabric outer layer.In one form, the foam is porous to allow moisture, (e.g., sweat), topass through the strap. In one form, the fabric outer layer comprisesloop material to engage with a hook material portion.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is extensible, e.g.resiliently extensible. For example the strap may be configured in useto be in tension, and to direct a force to draw a seal-forming structureinto sealing contact with a portion of a patient's face. In an examplethe strap may be configured as a tie.

In one form of the present technology, the positioning and stabilisingstructure comprises a first tie, the first tie being constructed andarranged so that in use at least a portion of an inferior edge thereofpasses superior to an otobasion superior of the patient's head andoverlays a portion of a parietal bone without overlaying the occipitalbone.

In one form of the present technology suitable for a nasal-only mask orfor a full-face mask, the positioning and stabilising structure includesa second tie, the second tie being constructed and arranged so that inuse at least a portion of a superior edge thereof passes inferior to anotobasion inferior of the patient's head and overlays or lies inferiorto the occipital bone of the patient's head.

In one form of the present technology suitable for a nasal-only mask orfor a full-face mask, the positioning and stabilising structure includesa third tie that is constructed and arranged to interconnect the firsttie and the second tie to reduce a tendency of the first tie and thesecond tie to move apart from one another.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is bendable and e.g.non-rigid. An advantage of this aspect is that the strap is morecomfortable for a patient to lie upon while the patient is sleeping.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap constructed to be breathable toallow moisture vapour to be transmitted through the strap,

In certain forms of the present technology, a system is providedcomprising more than one positioning and stabilizing structure 3300,9300, each being configured to provide a retaining force to correspondto a different size and/or shape range. For example the system maycomprise one form of positioning and stabilizing structure suitable fora large sized head, but not a small sized head, and another suitable fora small sized head, but not a large sized head.

5.3.3.1.1 Positioning and Stabilising Structure of the PresentTechnology

FIG. 5 depicts an example of the present technology, including apositioning and stabilising structure 3300. In this example, thepositioning and stabilising structure 3300 includes lateral portions3302 and superior portions 3304 in the form of conduits that direct aflow pressurised gas from a hub 3306 to ends 3314. The positioning andstabilising structure 3300 may be arranged such that the hub 3306 andthe decoupling structure 3500 are positioned superior to the patient'shead in use. As described below, the decoupling structure 3500 may berotatable within the hub 3306 and when the patient is wearing thepatient interface 3000, e.g., during therapy, the location of the hub3306 and the decoupling structure 3500 superior to the patient's headallows the patient to move more freely without becoming entangled withthe air circuit 4170.

The positioning and stabilising structure 3300 may be constructed ofsilicone. For example, the lateral portions 3302, the superior portions3304, the hub 3306, and the lateral ends 3314 may able constructed ormolded from a single piece of silicone.

The superior portions 3304 of the positioning and stabilising structure3300 have ridges and valleys (or concertina sections) that allow thesuperior portions 3304 to conform to the shape of the correspondingportion of the patient's head in use. The ridges and valleys of thesuperior portions 3304 allow the superior portions 3304 to be extendedand contracted along the longitudinal axis to accommodate larger orsmaller heads. The ridges and valleys of the superior portions 3304allow the superior portions 3304 to be flexed to different radii ofcurvature to accommodate patient heads of different shapes and sizes.

The lateral portions 3302 of the positioning and stabilising structure3300 may not be formed with the ridges and valleys of the superiorportions 3304. Therefore, the lateral portions 3302 may be lessextensible and flexible than the superior portions 3304, which may beadvantageous because there is less variability in the shape and size ofthe lateral sides of a patient's head.

The ends 3314 may connect to respective plenum chamber lateral ends3202. As described above, the plenum chamber lateral ends 3202 receivethe flow of pressurised gas from the positioning and stabilisingstructure 3300, which passes through the plenum chamber 3200, throughthe seal-forming structure 3100, and on to the patient's airways. Asdescribed above, the ends 3314 may connect to the plenum chamberconnectors 3204 of a respective plenum chamber lateral end 3202.

The positioning and stabilising structure 3300 may be structured andarranged to direct a force/tension provided by the lateral portions 3302into a partially superior and partially posterior force vector appliedto the plenum chamber 3200. The partially superior and partiallyposterior force vector urges, in particular, the textile membrane of theseal forming structure 3100 into sealing contact with an underside ofthe patient's nose contacting, e.g., at or below the pronasale and atleast above the upper vermillion.

The lateral portions 3302 may also each include a tab 3308 that receivesa posterior strap end portion 3311 of a posterior strap 3310. Theposterior strap 3310 may be length-adjustable, e.g., with a hook andloop material arrangement whereby one of the posterior strap end portion3311 and the remainder of the posterior strap 3310 includes hookmaterial on its exterior while the other includes loop material on itsexterior. The length adjustability of the posterior strap 3310 allowstension on the lateral portions 3302 to be increased to pull theseal-forming structure 3100 into sealing engagement with the patient'sface at a desired amount of pressure (i.e., sufficiently tight to avoidleaks while not so tight as to cause discomfort).

The lateral portions 3302 may also be provided with sleeves 3312 thatcushion the patient's face against the lateral portions 3302. Thesleeves 3312 may be constructed of a breathable textile material thathas a soft feel.

In an alternative example shown in FIG. 6, patient interface 6000includes a positioning and stabilizing structure 6300 having at leastone tube 6350 that is formed of a textile material (e.g., one or moresheets or layers of textile material) and receives pressurized air fromair delivery tube 6348 via connection port 6600. The tube 6350 includesleft arm 6305 and right arm 6307.

In some forms, the textile tube 6350 may be formed with a first sidethat is configured to contact the patient. This may be referred to asthe inner layer 6352. The textile conduit may also include a second sidethat is attached to the inner layer, but faces away from the patientthat may be referred to as the outer layer 6354. The inner layer and theouter layer may each be secured to each other along the edges of theinner layer and the outer layer such that a channel or passageway isformed between the seams of the inner layer and the outer layer. Thatis, the space between the seams remains unattached and forms an airpassage 6372. The inner layer and the outer layer may be joined usingvarious techniques that impart particular properties to the seam orjoint. For example, in some forms, the seams are formed using ultrasonicwelding, radio frequency welding, as well as cut and weld techniques.Heat may be applied in particular areas that activates a thermoset orthermoplastic material used in tube 6350. This heat may not only be usedto join the layers together, but may also be used to thermoform thelayers, such as outer layer 6354. Further, in some forms stitching or anadhesive such as a glue may be utilized to join the layers together. Insome forms, stitching is not used. In still further forms, materialbeyond what is located within the layers is not utilized to join theinner and outer layers of tube. For example, in some forms the inner andouter layers may be formed such that no additional material such as glueor stitching, is necessary to join the inner and outer layers together.

Each of the inner layer and the outer layer may include an interiorsurface and an exterior surface. The interior surface of the inner layeris the surface that faces the exterior layer. The interior surface ofthe exterior layer is the surface that faces the interior layer.Likewise, the exterior surface of the outer layer faces away from theinterior layer and the exterior surface of the inner layer faces awayfrom the outer layer. Further, in forms that include a single sheet, theinterior surface is the surface of the sheet that faces inwards andtowards itself.

In some forms, the sheet or sheets of the tube may include an airimpermeable layer or membrane. In some forms, the interior surface ofboth of the layers includes a membrane that is configured to restrict orrestrain air from passing through the layer from the interior surface tothe exterior surface. The impermeable layer may be a thin layer that isless than the thickness of the textile sheets of the inner layer orouter layer. In other forms, the impermeable layer may be greater thanthe thickness of the sheets of textiles of either of the layers. Theimpermeable layer or membrane or film may be completely impermeable toair transfer or may be formed to allow a predetermined rate or airtransfer and particular pressures.

The membrane may be formed of thermoplastic or thermoset materials suchthat when exposed to a particular temperature membrane material may beable to be molded or shaped into a particular form and then cures orsolidifies or sets upon cooling. In some forms the membrane may beformed of silicone or polyurethane. In some forms, outer layer 6354 maybe pre-formed such that in an unpressurized or supported state, outerlayer 6354 is pre-positioned and pre-formed to extend away from innerlayer 6352 between the opposing joints 6312. That is, outer layer 6354may support its own weight such that when not supported by pressurizedair or other support mechanism, outer layer 6354 remains spaced frominner layer 6352 between joints 6312.

In contrast, inner layer 6352 may be a floppy component. Inner layer6352 may be attached and secured to the edges of outer layer 6354 suchthat inner layer 6352 is a substantially planar layer.

As shown in FIG. 7, and in particular FIG. 8, inner layer 6352 comprisesa textile sheet 6360 along with membrane 6362. Textile sheet 6360 may beformed of felt, foam, woven, knit, or non-woven material or othernetwork of fibers.

Outer layer 6354 includes tube sheet 6364 and outer covering 6366. Insome forms, both sides of tube sheet 6364 may be covered with amembrane. As shown in FIG. 9, tube sheet 6364 includes membrane 6368exposed to the chamber of tube 6350 and membrane 6370 along an oppositesurface of tube sheet 6364. membrane 6368 may assist in providing a sealbetween inner layer 6352 and outer layer 6354 as well as forming an airtight tube. Membrane 6370 may assist in joining tube sheet 6364 to outercovering 6366.

It should also be appreciated that one or more aspects of the presenttechnology may be combinable with one or more aspects of: U.S.Provisional Application No. 62/821,878, filed Mar. 21, 2019 and entitled“Textile Headgear Tubing for a Patient Interface” or PCT/AU2019/050655,filed Jun. 25, 2019, each of which is hereby incorporated herein byreference in its entirety. For instance, the positioning and stabilizingstructure of the present technology may be identical to the positioningand stabilizing structure in any of the embodiments of the '968 or '655application. Additionally, the cushion assemblies or seal-formingstructures disclosed herein may replace any of the cushion assemblies orseal-forming structures in any of the patient interfaces disclosed inthe '968 or '655 application.

In another example shown in FIG. 38, patient interface 9000 includes apositioning and stabilizing structure 9300 having a pair of sideportions extending between the patient's eye and ear on respective sidesof the patient's head. The side portions may include a hole or otherconnector for connecting with the headgear attachment portions 9210 ofthe frame 9200. The positioning and stabilizing structure 9300 alsoincludes a rear strap 9310 extending around a rear portion of thepatient's head, and a crown strap 9312 extending over a crown section ofthe patient's head.

5.3.3.2 Vent

In one form, the patient interface 3000, 6000, 9000 includes a vent 3400constructed and arranged to allow for the washout of exhaled gases, e.g.carbon dioxide, as shown for example in FIG. 5.

In certain forms the vent 3400 is configured to allow a continuous ventflow from an interior of the cavity 3101 to ambient whilst the pressurewithin the plenum chamber is positive with respect to ambient. The vent3400 is configured such that the vent flow rate has a magnitudesufficient to reduce rebreathing of exhaled CO₂ by the patient whilemaintaining the therapeutic pressure in the plenum chamber in use.

One form of vent 3400 in accordance with the present technologycomprises a plurality of holes, for example, about 20 to about 80 holes,or about 40 to about 60 holes, or about 45 to about 55 holes.

The vent 3400 may be located in the plenum chamber 3200. The vent 3400may comprise a plurality of holes, as described above. The holes of thevent 3400 may be divided into two groups spaced apart laterally. Theaxis of the flow path through each of the holes of the vent 3400 may beparallel such that cross-flow is avoided to prevent generation ofadditional noise. The vent holes may be circular.

The holes of the vent 3400 may decrease in radius from the interior ofthe plenum chamber 3200 to the exterior. Each vent hole is provided witha draft angle. Each hole has a smaller diameter at its anterior end thanat its posterior end. The draft angle means that the holes do not have asmall cross section across the entire chassis thickness, which helps toprovide effective carbon dioxide wash out at high levels ofhumidification. Additionally, a larger draft angle may result in aplenum chamber 3200 that is easier to manufacture, especially when theplenum chamber 3200 is formed from an injection moulded plasticsmaterial. The draft angle enables relatively thick vent pins to be usedin the mould and easier ejection.

The holes of the vent 3400 may be provided in two sets towards themiddle of the plenum chamber 3200 and the sets may be symmetrical acrossthe centreline of the plenum chamber 3200. Providing a pattern ofmultiple vent holes may reduce noise and diffuse the flow concentration.

The holes of the vent 3400 may be placed at an optimum distance awayfrom the centreline of the plenum chamber 3200. Placing the holes of thevent 3400 towards the centreline may advantageously reduce the chancethat the vent holes are blocked when the patient is sleeping on theirside. However, placing the vent holes too close to the middle of theplenum chamber 3200 may result in excessive weakening of the plenumchamber 3200 at the centre, especially since the cross-section of theplenum chamber 3200 in the depicted examples is smallest at the centredue to the overall shape of the plenum chamber 3200. The location of theholes of the vent 3400 may avoid hole blockage during side sleep whileleaving the middle section of the chassis sufficiently strong.

The size of each vent hole and the number of vent holes may be optimisedto achieve a balance between noise reduction while achieving thenecessary carbon dioxide washout, even at extreme humidification. In thedepicted examples, the vent holes of the vent 3400 may not provide thetotal amount of venting for the system. The decoupling structure 3500may include a decoupling structure vent 3402. The decoupling structurevent 3402 may include one hole or a plurality of holes through thedecoupling structure 3500. The decoupling structure vent 3402 mayfunction to bleed off excess pressure generated by the RPT device 4000before reaching the patient, while the vent 3400 may function to washoutcarbon dioxide exhaled by the patient during therapy.

FIGS. 31 and 32 show an alternative example of the vent 3400 in whichholes are provided to a vent insert 13400 that attaches, removably orpermanently, to the plenum chamber 3200 at a vent insert opening. Thevent insert 13400 may be constructed from a material that is moreflexible than the material of the plenum chamber 3200.

5.3.3.3 Decoupling Structure(s)

In one form the patient interface 3000, 6000, 9000 includes at least onedecoupling structure, for example, a swivel or a ball and socket.

The hub 3306, described above, is connected to a decoupling structure3500, which is a rotatable elbow in these examples. The decouplingstructure 3500 may be rotatable 360° within the hub 3306 in use. Thedecoupling structure 3500 may be removable from the hub 3306 by manuallydepressing buttons 3504 to release catches (not shown) from within thehub 3306.

The decoupling structure 3500 may also include a swivel 3502 that allowsfor rotatable connection to an air circuit 4170.

The rotatability of the decoupling structure 3500, the decouplingstructure 3500 being in the form of an elbow, and the rotatability ofthe swivel 3502 on the decoupling structure 3500 may all increased thedegrees of freedom, which in turn reduce tube drag and torque on thepatient interface 3000 caused by the connection to the air circuit 4170.

5.3.3.4 Connection Port

Connection port 3600 allows for connection to the air circuit 4170.

5.3.3.5 Forehead Support

In one form, the patient interface includes a forehead support 3700.

5.3.3.6 Anti-Asphyxia Valve

In one form, the patient interface includes an anti-asphyxia valve.

5.3.3.7 Ports

In one form of the present technology, a patient interface 3000, 6000,9000 includes one or more ports that allow access to the volume withinthe cavity 3101. In one form this allows a clinician to supplysupplemental oxygen. In one form, this allows for the direct measurementof a property of gases within the cavity 3101, such as the pressure.

5.3.4 Full Face Cushion 5.3.4.1 First Illustrated Example

Referring to FIGS. 39-50, patient interface 14000 includes cushionassembly 14105 having a seal-forming structure 14100 that is configuredto seal separately around the patient's nares and mouth, i.e., anoro-nasal cushion assembly or ultra-compact full face mask. The cushionassembly 14105 is at least partially formed by a plenum chamber 14200and a seal-forming structure 14100 that is attached to the plenumchamber in accordance with an example of the present technology.

Referring to FIGS. 51-56, a cushion assembly 31105 is shown. Cushionassembly 31105 is similar to cushion assembly 14105 and has aseal-forming structure 31100 that is configured to seal separatelyaround the patient's nares and mouth, i.e., an oro-nasal cushionassembly or ultra-compact full face mask. The cushion assembly 31105 isat least partially formed by a plenum chamber 31200 and a seal-formingstructure 31100 that is attached to the plenum chamber in accordancewith an example of the present technology.

The cushion assembly 31105 includes nasal portion 31101, nasal portionholes 31103, oral portion 31102, oral portion hole 31104, cavity 31001,support structure 31120, sealing portion 31130, and vent 31400 which aresimilar to the features described in FIG. 39-50 and are not discussedseparately. A pair of plenum chamber holes are configured to receive aflow of air.

As described earlier, FIGS. 54-56 show grip pads 31150 on the surface ofthe textile membrane.

Plenum Chamber

The plenum chamber 14200 has a perimeter that is shaped to becomplementary to the surface contour of the face of an average person inthe region where a seal will form in use. In use, a marginal edge of theplenum chamber 14200 is positioned in close proximity to an adjacentsurface of the face. Actual contact with the face is provided by theseal-forming structure 14100. The seal-forming structure 14100 mayextend in use about the entire perimeter of the plenum chamber 14200.

In certain forms of the present technology, the plenum chamber 14200 isconstructed from a relatively rigid material (e.g., polycarbonate) ascompared to the seal-forming structure. In another example, the plenumchamber 14200 may be constructed from a transparent material, e.g. atransparent polycarbonate. The use of a transparent material can reducethe obtrusiveness of the patient interface, and help improve compliancewith therapy. The use of a transparent material can aid a clinician toobserve how the patient interface is located and functioning.

In certain forms of the present technology, the plenum chamber 14200 isconstructed from a translucent material. The use of a translucentmaterial can reduce the obtrusiveness of the patient interface, and helpimprove compliance with therapy.

The plenum chamber 14200 according to examples of the present technologymay include a plenum chamber hole on each lateral side. The plenumchamber hole may provide pneumatic communication between the conduitconnectors 14800, which are described in greater detail below, and thecavity 14001. A connection rim portion around each plenum chamber holemay facilitate a mechanical connection, e.g., snap-fit or friction fit,with the respective conduit connector. The plenum chamber 14200 may beconstructed of a sufficiently rigid material to provide audible and/ortactile feedback to the patient when the conduit connectors 14800 areconnected to or removed from the plenum chamber 14200.

The seal-forming structure 14100 may be sealingly connected to theplenum chamber 14200. The connection may be permanent or theseal-forming structure 14100 may be removable from the plenum chamber14200. The seal-forming structure 14100 may be overmoulded to the plenumchamber 14200. The seal-forming structure 14100 and the plenum chamber14200 may be joined by a mechanical connection in which no chemical bondis formed between the plenum chamber 14200 and the seal-formingstructure 14100.

Seal-Forming Structure

Referring to FIGS. 39-50, the seal-forming structure 14100 may include anasal portion 14101 having a pair of nasal portion holes 14103 to sealwith the patient's nares. The depicted examples provide two separateholes 14103 that each corresponds to one of the patient's nares toprovide the flow of air to both of the patient's nares. There may alsobe a bridge portion 14106 positioned between the naris openings 14103.In an alternative example, a single hole may be used to provide the flowof air to both of the patient's nares.

The seal-forming structure 14100 may include an oral portion 14102having an oral portion hole 14104 to seal with the patient's mouth.

The seal-forming structure 14100 may at least partly form a cavity 14001that is pressurized by the flow of air. The plenum chamber 14200 may bejoined to the seal-forming structure 14100 to further form the cavity14001.

The seal-forming structure 14100 may include a support structure 14120that provides support to a sealing portion 14130 (e.g., a textilemembrane). The sealing portion is configured to sealingly engage thepatient's face. Also, depending on the size and contours of thepatient's nose, the support structure may also sealingly engage thepatient's face.

The support structure 14120 may comprise a wall structure having atleast two regions of different thicknesses (e.g., portions of thesupport structure adjacent to or connecting to the plenum chamber 14200may be thicker than portions of the support structure adjacent to orconnecting to the sealing portion 14130 so as to provide structuralstability at the connection with the plenum chamber 14200 andflexibility at the interface with the patient). FIG. 84 illustrates anexample where portions (d1) of the support structure may be thicker thanportions (d2) of the support structure. For example, portions (d1) maybe adjacent to or connection to the plenum chamber and portions (d2) maybe adjacent to or connecting to the sealing portion so as to providestructural stability at the connection with the plenum chamber andflexibility at the interface with the patient. Alternatively, thethicker lateral support regions 3122 may be located, for example, at thecorner of nose region and/or regions of the oral portion of theseal-forming structure (and e.g., may connect directly to the textilemembrane), to ensure adequate sealing in the subalare region and/ormouth region of the patient's face.

As described above, the seal-forming structure 14100 may be sealinglyconnected to the plenum chamber 14200. The support structure 14120 maybe less rigid than the plenum chamber 14200 and may be constructed fromsilicone, foam (e.g., polyurethane foam), polyurethane solid material,thermoplastic elastomers (e.g., thermoplastic polyurethane), suitableplastics, or other suitable materials, as will be described later.Further, the sealing portion 14130 may be less rigid than the supportstructure 14120 and may be constructed from a textile material such asnylon, polyester, nylon and polyester mix, microfiber or polyurethane,for example, as will be described in more detail later.

The support structure 14120 may have an aperture formed thereinproviding an inner edge of the support structure along which the sealingportion 14130 (e.g., an outer perimeter of the sealing portion) may beattached to the support structure such that the sealing portion extendsradially inwardly of the seal-forming structure beyond or to a furtherextent than the support structure, as shown for example in FIGS. 43-46.For example, the sealing portion may be molded around the inner edge ofthe support structure or connected to the support structure in othersuitable ways, as will be described later.

In the example of FIG. 49, the support structure 14120 may extend intothe cavity 14001 forming an underlying cushion 14121 to provide supportto the sealing portion 14130. The underlying cushion 14121 and thesealing portion 14130 may form a dual wall structure around theperimeter of sealing portion. In alternative examples, a second or thirdunderlying cushion layer may be provided to form a triple or quadruplewall structure. In the example of FIG. 49, the underlying cushion isconstructed of a foam material (e.g., polyurethane foam). In analternative example, the underlying cushion 14122 may be constructed ofsilicone, as shown in FIG. 50. However, it will be recognized that theunderlying cushion may be constructed from other suitable materials(e.g., textile).

It should also be appreciated that one or more aspects of the presenttechnology may be combinable with one or more aspects of: U.S.Provisional Application No. 62/609,909, filed Dec. 22, 2017 or WO2019/119058, filed Dec. 21, 2018, both entitled “Conduit HeadgearConnector for Patient Interface,” Each of which is hereby incorporatedherein by reference in its entirety For instance, the conduits andpositioning and stabilizing structures of the present technology may beidentical to the conduits and positioning and stabilizing structures inany of the embodiments of the '909 or '058 application. Additionally,the cushion assemblies and seal-forming structures disclosed herein mayreplace any of the cushion assemblies (seal-forming structures andplenum chamber) and seal-forming structures in any of the patientinterfaces disclosed in the '909 or '058 application.

5.3.4.1.1 Positioning and Stabilising Structure

The seal-forming structure 14100 of the patient interface 14000 of thepresent technology may be held in sealing position in use by thepositioning and stabilising structure 14300.

In one form the positioning and stabilising structure 14300 provides aretention force at least sufficient to overcome the effect of thepositive pressure in the cavity 14001 to lift off the face.

In one form the positioning and stabilising structure 14300 provides aretention force to overcome the effect of the gravitational force on thepatient interface 14000.

In one form the positioning and stabilising structure 14300 provides aretention force as a safety margin to overcome the potential effect ofdisrupting forces on the patient interface 14000, such as from tubedrag, or accidental interference with the patient interface.

In one form of the present technology, a positioning and stabilisingstructure 14300 is provided that is configured in a manner consistentwith being worn by a patient while sleeping. In one example thepositioning and stabilising structure 14300 has a low profile, orcross-sectional thickness, to reduce the perceived or actual bulk of theapparatus. In one example, the positioning and stabilising structure14300 comprises at least one strap having a rectangular cross-section.In one example the positioning and stabilising structure 14300 comprisesat least one flat strap.

In one form of the present technology, a positioning and stabilisingstructure 14300 is provided that is configured so as not to be too largeand bulky to prevent the patient from lying in a supine sleepingposition with a back region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure 14300 is provided that is configured so as not to be too largeand bulky to prevent the patient from lying in a side sleeping positionwith a side region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure 14300 is provided with a decoupling portion located between ananterior portion of the positioning and stabilising structure 14300, anda posterior portion of the positioning and stabilising structure 14300.The decoupling portion does not resist compression and may be, e.g. aflexible or floppy strap. The decoupling portion is constructed andarranged so that when the patient lies with their head on a pillow, thepresence of the decoupling portion prevents a force on the posteriorportion from being transmitted along the positioning and stabilisingstructure 3300 and disrupting the seal.

In one form of the present technology, a positioning and stabilisingstructure 14300 comprises a strap constructed from a laminate of afabric patient-contacting layer, a foam inner layer and a fabric outerlayer. In one form, the foam is porous to allow moisture, (e.g., sweat),to pass through the strap. In one form, the fabric outer layer comprisesloop material to engage with a hook material portion.

In certain forms of the present technology, a positioning andstabilising structure 14300 comprises a strap that is extensible, e.g.resiliently extensible. For example the strap may be configured in useto be in tension, and to direct a force to draw a seal-forming structureinto sealing contact with a portion of a patient's face. In an examplethe strap may be configured as a tie.

In one form of the present technology, the positioning and stabilisingstructure may include a first tie (e.g., upper strap 14302 (FIG. 41)),the first tie being constructed and arranged so that in use at least aportion of an inferior edge thereof passes superior to an otobasionsuperior of the patient's head.

In one form of the present technology suitable for a full-face mask, thepositioning and stabilising structure includes a second tie (e.g., lowerstrap 14303 (FIG. 41)), the second tie being constructed and arranged sothat in use at least a portion of a superior edge thereof passesinferior to an otobasion inferior of the patient's head and overlays orlies inferior to the occipital bone of the patient's head.

In one form of the present technology suitable for a nasal-only mask orfor a full-face mask, the positioning and stabilising structure includesa third tie (e.g., strap connector 14304 (FIG. 39)) that is constructedand arranged to interconnect the first tie and the second tie to reducea tendency of the first tie and the second tie to move apart from oneanother.

In certain forms of the present technology, a positioning andstabilising structure 14300 comprises a strap that is bendable and e.g.non-rigid. An advantage of this aspect is that the strap is morecomfortable for a patient to lie upon while the patient is sleeping.

In certain forms of the present technology, a positioning andstabilising structure 14300 comprises a strap constructed to bebreathable to allow moisture vapour to be transmitted through the strap,

In certain forms of the present technology, a system is providedcomprising more than one positioning and stabilizing structure 14300,each being configured to provide a retaining force to correspond to adifferent size and/or shape range. For example, the system may compriseone form of positioning and stabilizing structure 14300 suitable for alarge sized head, but not a small sized head, and another suitable for asmall sized head, but not a large sized head.

The positioning and stabilising structure 14300 may include a clip 14301to secure respective ties, e.g., to the conduit connectors 14800 asshown in FIG. 39.

The clip 14301 and the conduit connector 14800 may each include a magnetarranged with opposing polarities to facilitate a connectiontherebetween.

5.3.4.1.2 Vent

In one form, the patient interface 14000 includes a vent 14400constructed and arranged to allow for the washout of exhaled gases, e.g.carbon dioxide, as shown in FIG. 39.

In certain forms, the vent 14400 is configured to allow a continuousvent flow from an interior of the plenum chamber 14200 to ambient whilstthe pressure within the plenum chamber is positive with respect toambient. The vent 14400 is configured such that the vent flow rate has amagnitude sufficient to reduce rebreathing of exhaled CO2 by the patientwhile maintaining the therapeutic pressure in the plenum chamber in use.

One form of vent 14400 in accordance with the present technologycomprises a plurality of holes, for example, about 20 to about 80 holes,or about 40 to about 60 holes, or about 45 to about 55 holes.

A vent 3400 may be located in the plenum chamber 14200, as shown in FIG.47. Alternatively, the vent 14400 is located in a decoupling structure,e.g., a swivel.

FIG. 39 shows an example of a vent 14400 provided on the connection port14600 (e.g., a swivel elbow). Variations of these examples may exclude avent 14400 from the connection port 14600.

The conduit connectors 14800, which are described in greater detailbelow, may also include vent features.

5.3.4.1.3 Decoupling Structure(s)

In one form, the patient interface 14000 includes at least onedecoupling structure, for example, a swivel or a ball and socket.

5.3.4.1.4 Connection Port

Connection port 14600 allows for connection to the air circuit 4170. Theconnection port 14600 according to an example of the present technologymay be connected to the connection port housing 14903. The connectionport 14600 may be swivelable relative to the connection port housing14903 and the connection to the air circuit 4170 may also be swivelable.

The connection port 14600 and the connection port housing 14903 may bepositioned superior to the patient's head in use.

5.3.4.1.5 Forehead Support

Examples of the patient interface of the present technology shown inFIGS. 39-50 do not include a forehead support. Variations of the patientinterface of the present technology may include a forehead support.

5.3.4.1.6 Conduits

The patient interface 14000 according to examples of the presenttechnology may include conduits 14900 to provide the flow of pressurizedair from the connection port 14600 to the cavity 14001 in the plenumchamber 14200. The conduits 14900 may be joined superior to thepatient's head at the connection port housing 14903 and may pass alonglateral sides of the patient's head between corresponding ones of thepatient's eyes and ears. The conduits 14900 may be connected to thecushion assembly 14105 (e.g., plenum chamber 14200) via conduitconnectors 14800, as described below, to provide the flow of pressurizedair to the cavity 14001.

The conduits 14900 may also stabilize and position the seal-formingstructure 14100 on the patient's face. Thus, the conduits 14900 mayfunction similarly to the ties of the positioning and stabilisingstructure 14300. Accordingly, the mechanical connection of the conduits14900 to the conduit connectors 14800 may be sufficient for tensionforces in the conduits 3900 to be transmitted to the seal-formingstructure 14100 through the conduit connectors 14800.

The conduits 14900 may include features of similar conduits disclosed inInternational Application Publication No. WO 2017/124155 A1, which ishereby incorporated by reference herein in its entirety. For example,the conduits 14900 of the present technology may include features of theheadgear tubes 3350 depicted in FIGS. 3A-3L of this document, as well asthe associated written description.

The conduits 14900 may also be provided with sleeves 14901 to cushionthe patient's face against the conduits 14900. The sleeves 14901 may beremovable. The sleeves 14901 may be made from a breathable material.

The conduits 14900 may also include tie connectors 14902 to facilitateconnection with ties of the positioning and stabilising structure 14300.

5.3.4.1.7 Conduit Connectors

The patient interface 14000, according to examples of the presenttechnology, may include conduit connectors 14800 to connect the conduits14900 to the cushion assembly 14105 to provide the flow of pressurizedair to the cavity 14001. The conduit connectors 14800 may each be formedwith a conduit connector housing 14801. The conduit connectors 14800 mayprovide other functions, as described below, such as venting of theplenum chamber 14200, connection to the positioning and stabilisingstructure 14300, and asphyxia prevention by inclusion of ananti-asphyxia valve 14850.

FIG. 43-50 show several views of the conduit connectors 14800 of thepatient interface 14000, according to examples of the presenttechnology.

In FIGS. 39-50, the conduit connectors 14800 are shown attached to theplenum chamber 14200 at the plenum chamber holes (not shown). As can beseen, there is one conduit connector 14800 on each lateral side of thecushion assembly 14105, and each conduit connector 14800 is connected toa plenum chamber hole on each corresponding lateral side of the cushionassembly 14105. The conduit connectors 14800 may each include a conduitconnector attachment structure to connect each of the conduit connectors14800 to a respective plenum chamber hole at the connection rim (notshown). The connection may be mechanical, e.g., snap-fit or frictionfit. The connection may also be removable. The material of the conduitconnectors 14800 and the material of the plenum chamber 14200 may eachbe selected to facilitate the desired connection features. For example,the material of the conduit connectors 14800 and the material of theplenum chamber 14200 may each be relatively rigid to permit the audibleand/or tactile feedback associated with a snap-fit. The material of theconduit connectors 14800 and the material of the plenum chamber 14200may be different in at least one aspect or the materials may be thesame. The conduit connectors 14800 may also be permanently connected tothe plenum chamber at the plenum chamber holes. For example, the conduitconnectors 14800 may be ultrasonically welded to the plenum chamber14200. The connection between the conduit connectors 14800 and theplenum chamber 14200, whether removable or permanent, may also bedesigned to be sufficiently strong such that tension from the conduits14900 can be transferred to the plenum chamber 14200 without disruptingthe connection because, as explained above, the conduit connectors 14800may facilitate positioning and stabilising of the seal-forming structure14100 on the patient's head.

The conduit connectors 14800 may also be attached to lateral sides ofthe plenum chamber 14200 to improve aesthetics of the patient interface14000. As explained above, the plenum chamber 14200 may be constructedof a transparent or translucent material, which may allow visibility ofthe patient's facial features. By locating the conduit connectors 14800laterally on the plenum chamber, e.g., as shown in the depictedexamples, more of the patient's face is visible, and that arrangementcan improve aesthetics of the patient interface 14000. This contrastswith alternative designs where an elbow and air circuit may be joined tothe center of the plenum chamber 14200, thereby obstructing the view ofthe patient's face.

The conduit connectors 14800 may also each include a conduit connectionend 14802 that connects to a respective conduit 14900. The connectionbetween the conduits 14900 and the conduit connectors 14800 at theconduit connection ends 14802 may be removable or permanent. A conduitconnector inlet hole 14803 may be formed in the conduit connectorhousing 14801 at the conduit connection end 14802 to receive the flow ofpressurized air. The conduit connectors 14800 may include structure,e.g., an undercut, to facilitate a removable, snap-fit connection withcorresponding conduits 14900, and each conduit 14900 may include arelatively rigid structure at the end that connects to the conduitconnectors 14800 to facilitate such a connection. The conduit connectors14800 may also be joined to the conduits 14900 with a friction fit.Again, as explained above, the conduits 14900 may provide a positioningand stabilising function to locate the seal-forming structure in atherapeutically effective sealing position on the patient's face, andtherefore the connection between the conduits 14900 and the conduitconnectors 14800 at the conduit connection ends 14802 may besufficiently secure to permit tension forces from the conduits 14900 tobe transmitted to the conduit connectors 14800 without disrupting theconnection between the conduits 14900 and the conduit connectors 14800at the conduit connection ends 14802.

The conduit connectors 14800 may also provide a venting function for thepatient interface 14000. The conduit connector housing 14801 may includea vent inlet that is in pneumatic communication with the cavity 14001when the patient interface 14000 is assembled. The conduit connectorhousing 14801 may also include at least one conduit connector vent hole14831. As can be seen in the depicted examples, each conduit connectorhousing 14801 includes a plurality of conduit connector vent holes14831. This ensures adequate mixing of newly introduced air and airalready present in the plenum chamber 14200, which can enhance carbondioxide washout and increase the amount of fresh air provided to thepatient for respiration.

As shown in FIG. 39-41, the conduit connectors 3800 may also provide aconnection to ties of the positioning and stabilising structure 3300.The inferior ties may be joined to the conduit connectors 3800 withclips 14301. The clips 14301 and the conduit connectors 14800 mayinclude magnets with opposing polarities to facilitate the connection.The connection between the ties of the positioning and stabilisingstructure 14300 and the conduit connectors 14800 may be releasable. Thetension from the inferior ties of the positioning and stabilisingstructure 14300 may urge inferior portions of the seal-forming structure14100 into sealing engagement with the patient's face, e.g., around themouth. Alternatively, structure to connect to the clips 14301 may beformed directly on the conduit connector housing 14801.

5.3.4.1.8 Anti-Asphyxia Valve

In one form, the patient interface 14000 includes an anti-asphyxiavalve. As best shown in FIGS. 47 and 48, each of the conduit connectors14800 may include an anti-asphyxia valve assembly 14850. Accordingly,the patient interface 14000 may include two anti-asphyxia valveassemblies 14850. Each of the anti-asphyxia valve assemblies 14850 mayoperate independent of the other, i.e., in response to a cessation ofthe flow of pressurized air. For example, if the patient is sleeping onhis or her side when there is a cessation of the flow of pressurized airand one of the anti-asphyxia valve assemblies 14850 is occluded, e.g.,by a pillow, the other of the anti-asphyxia valve assemblies 14850 canfunction to prevent the patient from being asphyxiated.

5.3.4.1.9 Ports

In one form of the present technology, a patient interface 14000includes one or more ports that allow access to the volume within theplenum chamber 4200. In one form this allows a clinician to supplysupplemental oxygen. In one form, this allows for the direct measurementof a property of gases within the plenum chamber 14200, such as thepressure.

5.3.4.2 Second Illustrated Example

FIGS. 57 to 66 show a patient interface 30000 according to anotherexample of the present technology. Patient interface 30000 includescushion assembly 30105 having a seal-forming structure 30100 that isconfigured to seal separately around the patient's nares and mouth,i.e., an oro-nasal cushion assembly or ultra-compact full face mask. Thecushion assembly 30105 is at least partially formed by a plenum chamber(or shell) 30200 and a seal-forming structure 30100 that is attached tothe plenum chamber in accordance with an example of the presenttechnology.

The cushion assembly 30105 includes nasal portion 30101, nasal portionholes 30103, oral portion 30102, oral portion hole 30104, cavity 30001,support structure 30120, and sealing portion 30130 which are similar tothe features described in FIGS. 39-56 and are not discussed separately.An inlet port 30240 is formed in the plenum chamber and is configured toreceive a flow of air for an air circuit.

5.3.4.2.1 Positioning and Stabilising Structure

FIGS. 57-66 show a patient interface 30000 according to one example ofthe present technology having a positioning and stabilising structure30300 and a plenum chamber 30200 having a seal forming structure 30100.The positioning and stabilising structure 30300 in this examplecomprises a frame 30350 and a plurality of headgear straps connected tothe frame 30350.

The plenum chamber 30200 of the patient interface 30000 is connected tothe frame 30350. The plenum chamber 30200 may connect to the frame 30350via a snap fit connection. In other examples, the plenum chamber mayform a different type of removable connection to the frame, snap fit,removable press fit or otherwise, or may be permanently connected to theframe.

The positioning and stabilising structure 30300 may comprise a pluralityof straps or strap portions connecting to the frame 30350 and passingaround the patient's head in order to support the plenum chamber insealing position against the patient's face. It will be understood thata single “strap” may be formed by multiple lengths of material(s) thathave been cut or formed separately and then joined together at theirends to create a longer length or single “strap” may be a single lengthof material(s).

In the example illustrated in FIGS. 57-66, the positioning andstabilising structure 30300 comprises a pair of upper straps 30310. Eachupper strap is configured to pass between a respective eye and ear ofthe patient. Additionally, the positioning and stabilising structurecomprises a pair of lower straps 30320 configured to lie over thepatient's cheeks below the patient's cheekbones. In this example, theplenum chamber is held in position via a four-point connection toheadgear straps via the frame 30350.

The frame is shown in isolation in FIGS. 63-64. The frame comprises aframe inlet connection port 30354. The frame inlet connection port 30354may be configured to connect to a source of pressurised breathable gas,such as air. In one example, the frame inlet connection port 30354 maybe configured to enable connection to a swivel elbow assembly 30610which provides a connection port 30600 for connection with an aircircuit 4170. The frame inlet connection port in this example comprisesa connection rim 30355. The connection rim 30355 may comprise a radiallyoutwardly extending flange. The swivel elbow assembly 30610 may form areleasable snap-fit with the connection rim, creating a fluid connectionbetween the swivel elbow assembly and the frame. The opposite side ofthe frame inlet connection port 30354 is configured to fluidly connectto the plenum chamber. The frame 30350 therefore enables a fluidconnection between the swivel elbow assembly 30610 and the interior ofthe plenum chamber 30200.

The frame 30350 also comprises a pair of opposed upper strap connectionpoints 30315 to which the upper straps 30310 connect. In this example,each upper strap connection point comprises an aperture formed in theframe. Each upper strap 30310 is able to connect to a respective upperstrap connection point 30315 by passing through the aperture, loopingback onto itself and securing to itself. Each upper strap may secured toitself via hook and loop materials configured to releasably bind to eachother upon contact. In alternative examples, each upper strap 30310 maypass through a respective aperture, loop back onto itself and be securedonto itself with a band, clip or the like. In further alternativeexamples, the upper straps may connect to the frame via side releasebuckle connections.

The frame 30350 also comprises a pair of opposed lower strap connectionpoints 30325 to which the lower straps 30320 connect. In this example,each lower strap connection point comprises a magnet. Each lower strapcomprises a lower strap clip 30326 comprising a magnet or material thatis attracted to the magnet at the lower strap connection point 30325. Inthis example, each lower strap clip 30326 comprises an aperture throughwhich the end of a respective lower strap is able to pass and then loopback and be secured onto itself, for example with hook and loopmaterial, a band, a clip or the like. In alternative examples, the lowerstraps may connect to the frame via side release buckle connections,onto hooks or via any other suitable connection.

In an example, the frame 30350 and upper strap connection points 30315are structured and arranged to direct a force/tension provided by theupper straps 30310 into a partially superior and partially posteriorforce vector applied to the plenum chamber 30200. The partially superiorand partially posterior force vector urges, in particular, the nasalportion 30101 of the seal forming structure 3100 into sealing contactwith the lower periphery of the patient's nose and the patient's upperlip.

The upper straps 30310 may each be selectively adjustable. For example,the effective length of each of the upper straps may be varied bychanging how much of the upper strap is passed through the aperture atthe respective upper strap connection point 30315 and looped back onitself. Passing more of the upper strap through the aperture effectivelyreduces the length of the upper strap, allowing the force vectors to bemodified and the fit of the patient interface to be adjusted.

In an example, the frame 30350 and the lower strap connection points30325 are structured and arranged to direct a force/tension provided bythe lower straps 30320 into a partially posterior and partially inferiorforce vector applied to the plenum chamber. The partially posterior andpartially inferior force vector urges, in particular, the oral portion30102 into sealing contact with the patient's face around the peripheryof the patient's mouth. The partially inferior force applied to theframe by the lower straps may balances the partially superior forceapplied by the upper straps along with any inferiorly directed forcethat the patient's nose may apply onto the seal forming structure.

The lower straps 30320 may each by selectively adjustable. For example,the effective length of each of the lower straps may be varied bychanging how much of each lower strap is passed through the aperture inthe respective lower strap clip 30326 and looped back on itself. Passingmore of each lower strap through the aperture effectively reduces thelength of the lower strap, allowing the force vectors to be modified andthe fit of the patient interface to be adjusted.

The positioning and stabilising structure 30300 may also comprise one ormore of a top crown strap 30330, a pair of lateral crown straps 30332and a neck strap 30334. In the example illustrated in FIGS. 57-66, theupper straps 30310 and lower straps 30320 are connected to ends of a topcrown strap 30330. The top crown strap is configured to pass around thepatient's head and lie against superiorly and posteriorly facingsurfaces. The top crown strap 30330 may be configured to overlie theparietal bone of the patient's skull. Each end of the top crown strapconnects to a respective one of the upper straps 30310 and also to arespective one of a pair of lateral crown straps 30332. Each one of thelateral crown straps connects between the upper strap and the lowerstrap on a respective side of the patient's head. The inferior ends ofthe lateral crown straps 30332 are connected to each other by a neckstrap 30334. The neck strap may be configured to pass across thesagittal plane and lie against inferior and/or posterior facing surfacesof the patient's head or lie against the back of the patient's neck. Theneck strap may overlie, or lie inferior to, the occipital bone of thepatient's skull.

The length of the top crown strap 30330 may be selectively adjustable.The top crown strap 30330 is formed by two strap portions which areconnected by a link having a pair of apertures. Each of the two strapportions forming the top crown strap is able to pass through arespective one of the apertures then loop back and secure to itself, forexample via hook and loop material, a further clip, a band or the like.The amount of each top strap portion that passes through the link can bevaried to adjust the length of the top crown strap 30330 and in turnadjust the fit of the positioning and stabilising structure.

Once all the headgear straps have been adjusted and the desired fit ofthe patient interface 30000 has been achieved, the magnetic clipconnection provided by the lower strap clips 30326 enables the lowerstraps 30320 to be quickly disengaged from the lower strap connectionpoints 30325 on the frame 30350, allowing the patient interface 30000 tobe removed from the patient without adjustment of straps. Similarly,when the patient dons the patient interface again, the lower strap clipscan be quickly engaged at the lower strap connection points to fit thepatient interface without the need to adjust straps. Further advantagesand features of a positioning and stabilising structure comprisingmagnetic clips are described in WO 2014/110622, the entire contents ofwhich are incorporated herein by reference.

In certain forms of the present technology, a system is providedcomprising more than one positioning and stabilizing structure, eachbeing configured to provide a retaining force to correspond to adifferent size and/or shape range. For example the system may compriseone form of positioning and stabilizing structure suitable for a largesized head, but not a small sized head, and another. suitable for asmall sized head, but not a large sized head.

Also, it should be appreciated that one or more aspects of the presenttechnology may be combinable with one or more aspects of:PCT/AU2019/050278, filed Mar. 28, 2019 and entitled “Patient Interface,”the entire contents of which are hereby incorporated herein by referencein their entirety.

5.3.4.2.2 Vent

In one form, the patient interface 30000 includes a vent 30400constructed and arranged to allow for the washout of exhaled gases, e.g.carbon dioxide.

In certain forms the vent 30400 is configured to allow a continuous ventflow from an interior of the plenum chamber 30200 to ambient whilst thepressure within the plenum chamber is positive with respect to ambient.The vent is configured such that the vent flow rate has a magnitudesufficient to reduce rebreathing of exhaled CO₂ by the patient whilemaintaining the therapeutic pressure in the plenum chamber in use.

One form of vent in accordance with the present technology comprises aplurality of holes, for example, about 20 to about 80 holes, or about 40to about 60 holes, or about 45 to about 55 holes.

The vent 30400 may be located in the plenum chamber. Alternatively, thevent is located in a decoupling structure, e.g., a swivel.

In the example illustrated in FIGS. 57-66, the patient interface 30000comprises a vent 30400. The vent in this example comprises passageswithin the frame and swivel elbow assembly through which air can flowfrom the interior of the plenum chamber to atmosphere. As shown in FIG.59, air can flow into the swivel elbow assembly 30610 and then out toatmosphere through exterior holes of the swivel elbow assembly formingpart of the vent 30400. The swivel elbow assembly 30610 may besubstantially as described in International Publication No. WO2017/049357 A1, the entire contents of which are incorporated herein byreference.

5.3.4.2.3 Decoupling Structure(s)

In one form the patient interface 30000 includes at least one decouplingstructure, for example, a swivel or a ball and socket.

5.3.4.2.4 Connection Port

Connection port 30600 allows for connection to the air circuit 4170.

5.3.4.2.5 Forehead Support

In one form, the patient interface 30000 includes a forehead support3700 such as that shown in FIG. 3A. In other examples, the patientinterface may exclude a forehead support. Furthermore, the patientinterface 30000 may be configured not to contact the patient's foreheadat all.

5.3.4.2.6 Anti-Asphyxia Valve

In one form, the patient interface 30000 includes an anti-asphyxiavalve.

5.3.4.2.7 Ports

In one form of the present technology, a patient interface 30000includes one or more ports that allow access to the volume within theplenum chamber. In one form this allows a clinician to supplysupplemental oxygen. In one form, this allows for the direct measurementof a property of gases within the plenum chamber 302000, such as thepressure.

5.3.4.3 Third Illustrated Example

FIGS. 67 to 77 show a patient interface 16000 according to anotherexample of the present technology. The patient interface includes aframe assembly 16100, a cushion assembly 16175 including a seal-formingstructure 16200, an air delivery connector (e.g., elbow assembly 16600),and a positioning and stabilising structure (e.g., headgear 16800including upper side straps 16802, lower side straps 16804, and crownstrap 16806). In use, one form of the seal-forming structure 16200 isarranged to surround an entrance to the airways of the patient 1000 soas to facilitate the supply of air at positive pressure to the airways.In the example shown in FIGS. 46-56, the patient interface is afull-face/oro-nasal interface type including a seal-forming structure16200 structured to form a seal around the patient's nose and mouth.However, aspects of the present technology may be adapted for use withother suitable interface types, e.g., nasal interface, nasal prongs,pillows, etc.

The seal-forming structure 16200 may also be commonly referred to as acushion. FIGS. 67 and 68 are exemplary views of the patient interface16000 with arm covers 16750 for upper arms 16134 of the frame assembly16100 attached, and FIG. 69 is an exemplary view of the patientinterface 16000 with the headgear 16800 and the arm covers 16750removed.

In this example, the cushion assembly 16175 connects to the frameassembly 16100 (via a first retention feature on the frame assembly)independently of the elbow assembly 16600, and the elbow assembly 16600connects to the frame assembly 16100 (via a second retention feature onthe frame assembly) independently of the cushion assembly 16175. Thatis, the retention connections of the cushion assembly 16175 and theelbow assembly 16600 to the frame assembly 16100 are separate anddistinct from one another and allow independentengagement/disengagement.

In the example of patient interface 16000, a first seal for the air flowpath is formed between the elbow assembly 16600 and the frame assembly16100, and a separate second seal is formed between the frame assembly16100 and the cushion assembly 16175. In this example, the frameassembly 16100 is provided in the air flow path. That is, the elbowassembly 16600 is structured to establish a hard-to-hard connection anddynamic seal with the frame assembly 16100, and the cushion assembly16175 is structured to establish a separate hard-to-hard connection andstatic seal with the frame assembly 16100.

Also, in the example of patient interface 16000, the frame assembly16100 includes a lockout feature along the opening 16105 that isstructured and arranged to prevent direct connection or insertion of theair circuit 4170, e.g., air delivery tube. This arrangement requires useof the elbow assembly 16600 to interconnect the frame assembly 16100 andthe air circuit 4170, thereby ensuring that the elbow assembly 16600(and its vent and anti-asphyxia valve (AAV)) are present in the system.

Frame Assembly

Still referring to FIGS. 67-77, the frame assembly 16100 includes ashroud or wall member 16110, a pair (i.e., right and left) of upperheadgear connector arms 16134 (each comprising two flexible portions16140, 16145) extending from respective sides of an upper portion of theshroud 16110, and a pair (i.e., right and left) of lower headgearconnector arms 16154 extending from respective sides of a lower portionof the shroud 16110. Each lower headgear connector arm 16154 comprisesthe magnetic connector 16155 (including encased magnet) structured tolocate and connect to the headgear clip 16160 (including encased magnet)provided to the respective lower headgear strap 16804 of the headgear.

In the illustrated example, the opening 16105 of the shroud 16110 (e.g.,constructed of a relatively hard plastic material such as polycarbonate)is bounded by an outer annular flange and an inner annular flange.

Cushion Assembly & Elbow Assembly

Referring to FIGS. 67-77, the cushion assembly 16175 includes a mainbody, chassis, plenum chamber or shell 16180 that is connected orotherwise provided to the seal-forming structure or cushion 16200 (seeFIGS. 70 and 71). The shell 16180 may be permanently (e.g., co-molded,overmolded) or removably (e.g., mechanical connection) connected to thecushion 16200. In an example, the cushion 16200 is constructed of arelatively flexible or pliable material and the shell 16180 isconstructed of a relatively rigid material (e.g., polycarbonate). Theshell 16180 and the cushion 16200 cooperate to form the cavity 16500(e.g., see FIGS. 70, 71 and 73). The shell 16180 includes an opening16305 by which breathable gas is delivered to the cavity 16500. Theopening 16305 is bounded by an annular flange 16310 which is adapted toconnect to the frame assembly 16100.

The shell 6180 has multiple functions. For example, it at leastpartially forms the cavity for delivery of pressurised gases to theentrance of a patient's airways. The shell 6180 is a rigid structurethat directs a force onto the seal-forming structure for sealing to apatients face. The force is provided by tension forces from tighteningthe headgear straps. These forces are translated from a pair of upperand lower headgear straps to the corresponding upper and lower arms. Inan example, the upper and lower arms are provided with the frameassembly, which provides the headgear tension forces to the shell 16180.

The shell 16180 of the cushion assembly 16175 is repeatedly engageablewith and removably disengageable from the shroud 16110 of the frameassembly 16100 via a mechanical connection, e.g., snap-fit connection.The inner annular flange of the shroud 16110 extends through the opening16305 of the shell 16180, and the tabs or catches of the flange engageor interlock on a posterior side of the annular flange 16310 of theshell 16180 so as to releasably connect the frame assembly 16100 to thecushion assembly 16175. Such connection maintains ease of use, providesa sealed hard to hard connection, minimizes rattling and rockingmovement between components, and reduces impact on stability. Also, suchconnection stably holds the cushion assembly 16175 in position, whileallowing the appropriate force vectors to be imparted onto the cushionassembly 16175 for seal.

In the example shown in FIG. 67, the elbow assembly 16600 includes afirst end portion 16610 with pinch arms 16650 to releasably engage withthe frame assembly 16100 (and form a swivel connection therewith) and asecond end portion 16620 adapted to connect to the air circuit 4170,e.g., via a swivel connector 16625. The elbow assembly 16600 isstructured to establish a hard-to-hard connection and seal with theframe assembly 16100.

In this example, the first end portion 16610 includes inner and outerradial walls defining a radial channel leading to a plurality of ventholes 16700 to permit the exit of exhausted gases from the patientinterface.

Also, it should be appreciated that one or more aspects of the presenttechnology may be combinable with one or more aspects of: U.S.Application Publication No. 2018/0250486, filed Mar. 12, 2018 andentitled “Patient Interface,” the entire contents of which are herebyincorporated herein by reference in their entirety. For instance, thecushion assembly 16175 disclosed herein may replace the cushion assemblyin any of the patient interface embodiments disclosed in the '486publication. Furthermore, the seal-forming structure 16200 disclosedherein made replace the seal-forming structure in any of the patientinterface embodiments disclosed in the '486 publication.

Seal-Forming Structure

As described above, the shell 16180 is sealingly connected or otherwiseprovided to the seal-forming structure or cushion 16200, and the shell16180 and the cushion 16200 cooperate to form the cavity 16500.

The cushion 16200 may include a support structure 16220 that providessupport to a sealing portion 16230 (e.g., a textile membrane). Thesealing portion is configured to sealingly engage the patient's face.

The support structure 16220 may comprise a wall structure having atleast two regions of different thickness (e.g., portions of the supportstructure adjacent to or connecting to the shell 16180 may be thickerthan portions of the support structure adjacent to or connecting to thesealing portion 16230 so as to provide structural stability at theconnection with the shell 16180 and flexibility at the interface withthe patient). FIG. 84 illustrates an example where portions (d1) of thesupport structure may be thicker than portions (d2) of the supportstructure. For example, portions (d!) may be adjacent to or connectionto the plenum chamber and portions (d2) may be adjacent to or connectingto the sealing portion so as to provide structural stability at theconnection with the frame and flexibility at the interface with thepatient. Alternatively, the thicker lateral support regions 3122 may belocated, for example, at the lower cheek region of the seal-formingstructure (and e.g., may connect directly to the textile membrane), toensure adequate sealing in the lower cheek region of the patient's face.

The support structure 16220 may be less rigid than the shell 16180 andmay be constructed from silicone, foam (e.g., polyurethane foam),polyurethane solid material, thermoplastic elastomers (e.g.,thermoplastic polyurethane), suitable plastics, or other suitablematerials, as will be described later. Further, the sealing portion16230 may be less rigid than the support structure 16220 and may beconstructed from a textile material such as nylon, polyester, nylon andpolyester mix, microfiber or polyurethane, for example, as will bedescribed in more detail later.

The support structure 16220 may have an aperture formed thereinproviding an inner edge of the support structure along which the sealingportion 16230 (e.g., an outer perimeter of the sealing portion) may beattached to the support structure such that the sealing portion extendsradially inwardly of the seal-forming structure beyond or to a furtherextent than the support structure, as shown for example in FIGS. 71 and73-77. For example, the sealing portion may be molded around the inneredge of the support structure or connected to the support structure inother suitable ways, as will be described later.

The support structure 16220 may extend into the cavity 16500 forming anunderlying cushion 16221 to provide support to the sealing portion16230, as shown in FIGS. 73 and 77. The underlying cushion 16221 and thesealing portion 16230 may form a dual wall structure around theperimeter of sealing portion. In alternative examples, a second or thirdunderlying cushion layer may be provided to form a triple or quadruplewall structure. The underlying cushion may be constructed of the samematerials as the support structure and may also be constructed of othersuitable materials (e.g., textile).

5.3.4.3.1 Positioning and Stabilising Structure

The seal-forming structure of the patient interface of the presenttechnology may be held in sealing position in use by the positioning andstabilising structure.

In one form of the present technology, a positioning and stabilisingstructure is provided that is configured in a manner consistent withbeing worn by a patient while sleeping. In one example the positioningand stabilising structure has a low profile, or cross-sectionalthickness, to reduce the perceived or actual bulk of the apparatus. Inone example, the positioning and stabilising structure comprises atleast one strap having a rectangular cross-section. In one example thepositioning and stabilising structure comprises at least one flat strap.

In one form of the present technology, a positioning and stabilisingstructure 3300 comprises a strap constructed from a laminate of a fabricpatient-contacting layer, a foam inner layer and a fabric outer layer.In one form, the foam is porous to allow moisture, (e.g., sweat), topass through the strap. In one form, the fabric outer layer comprisesloop material to engage with a hook material portion.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is extensible, e.g.resiliently extensible. For example the strap may be configured in useto be in tension, and to direct a force to draw a cushion into sealingcontact with a portion of a patient's face. In an example the strap maybe configured as a tie.

In certain forms of the present technology, a positioning andstabilising structure comprises a strap that is bendable and e.g.non-rigid. An advantage of this aspect is that the strap is morecomfortable for a patient to lie upon while the patient is sleeping.

In certain forms of the present technology, a positioning andstabilizing structure provides a retaining force configured tocorrespond to a particular size of head and/or shape of face. Forexample one form of positioning and stabilizing structure provides aretaining force suitable for a large sized head, but not a small sizedhead. In another example, a form of positioning and stabilizingstructure provides a retaining force suitable for a small sized head,but not a large sized head.

5.3.4.3.2 Vent

In one form, the patient interface includes a vent constructed andarranged to allow for the washout of exhaled gases, e.g. carbon dioxide.

One form of vent in accordance with the present technology comprises aplurality of holes, for example, about 20 to about 80 holes, or about 40to about 60 holes, or about 45 to about 55 holes.

The vent may be located in the plenum chamber or shell. Alternatively,the vent is located in a decoupling structure, e.g., a swivel.

5.3.4.3.3 Decoupling Structure(s)

In one form the patient interface includes at least one decouplingstructure, for example, a swivel or a ball and socket.

5.3.4.3.4 Connection Port

Connection port allows for connection to the air circuit.

5.3.4.3.5 Forehead Support

In the illustrated example, the frame assembly 6100 is provided withouta forehead support.

In another form, the patient interface may include a forehead support,e.g., the frame assembly may include a forehead support.

5.3.4.3.6 Anti-Asphyxia Valve

In one form, the patient interface includes an anti-asphyxia valve.

5.3.4.3.7 Ports

In one form of the present technology, a patient interface includes oneor more ports that allow access to the volume within the cavity. In oneform this allows a clinician to supply supplemental oxygen. In one form,this allows for the direct measurement of a property of gases within thecavity, such as the pressure.

5.3.5 Support Structure and Sealing Portion Arrangements

The support structures and sealing portions in the examples describedabove may have a number of different configurations and arrangements.

In use, the sealing portion (e.g., textile membrane) may be maintainedin sealing contact with the patient's face by 1) tension (e.g., a lighttension) in the textile membrane and/or a resilient stretchcharacteristic (e.g., elasticity) of the material (e.g., the textilematerial, the air impermeable layer material and/or the compositematerial of the textile membrane) of the sealing portion; 2) a reactivestress of the support structure; 3) a pre-formed state of the textilemembrane formed as a non-tensioned, yet substantially constant surface,without leak causing interruptions such as creases, folds, buckles orwrinkles in the textile membrane; and/or 4) air pressure within thecavity against an inside surface of the sealing portion. Each of thesefactors may contribute to the sealing portion being under constanttension such that the sealing portion complies to the anthropometriccontours of the patient's face, thereby minimizing wrinkles or blow-outand maximizing the contact area of the sealing portion.

In some examples, the sealing portion may comprise a relatively thin,compliant, stretchable, elastic material, such as a textile membranecomprising a suitable textile material (e.g., nylon, polyester, nylonand polyester mix, microfiber or polyurethane). The sealing portion maybe held taut and in tension by the support structure prior to and duringuse. The sealing portion may be molded or otherwise attached (e.g.,adhered, glued) to the support structure so that the sealing portion ispre-tensioned (slightly stretched) so that there are no wrinkles in thematerial of the sealing portion. This may be advantageous in ensuringthat the sealing portion forms a smooth and continuous seal on thepatient's face without any folded sections through which air may leak.Further, the sealing portion may be shaped or have curvature impartedthereto, e.g., by thermoforming, so that the sealing portion holds itsown shape. The support structure may also impart curvature to thesealing portion.

For example, as shown in FIGS. 11-17 and 23-37 the sealing portion mayhave a concave curved profile from one lateral side (right) to anopposing lateral side (left) (e.g., positive curvature in a left-rightdirection) to cradle the patient's nose.

In some forms, as shown for example in FIGS. 10-66, the patient's noseis not intended to be received in the cavity formed by the plenumchamber and the seal-forming structure. Instead, unlike conventionalmasks, the patient's nose is intended to press against the textilemembrane which in turn accommodates the contours of the patient's faceto comfortably form a reliable seal with the patient's airways. In theway, the textile membrane may stretch to accommodate the patient's face.The bridge portion 3104, 1406 extending between the naris openings mayassist maintaining the textile membrane in a taut manner prior to and/orduring use. The bridge portion may also function to help provide, byeliminating a central opening in the textile membrane, a sealing portionthat presses against the patient's nose rather than receives thepatient's nose in the cavity. This creates a different sealingexperience as compared to conventional masks. This sealing experiencemay provide enhanced comfort due to contact with a compliant textilemembrane rather than the more rigid materials of conventional masks orconventional sealing arrangements where the sealing portion has asmaller contact area around a perimeter of the nose and/or mouth.

The sealing portion may be constructed from a single or a plurality oflayers of material (e.g., textile material). The textile membrane(and/or the textile material of the textile membrane) may exhibit a lowspring constant (i.e., highly compliant) in both warp and weft. Unlikeconventional masks (e.g., silicone sealing membrane), where a fixedcushion may cause a patient's skin to distort to form an effective seal,the textile membrane may have a material spring constant and springlength (i.e., the amount of material available to stretch) such that thetextile membrane is more compliant than the patient's skin so as to morereadily conform to the patient's facial features. This may improvecomfort of the mask and reduce formation of localized pressure “hotspots.”

Compared to conventional silicone membranes and compression foam seals,the sealing portion of the present technology has a more flexiblestructural stiffness and therefore has a dynamic spring backcharacteristic that enables the sealing portion to recover more quicklywhen disturbed by an external force. Further, due to the lowerstructural stiffness a smaller seal force is required allowing thesealing portion to be more comfortable and create less facial marksduring use.

The textile membrane may exhibit variable tension forces across thematerial (e.g., less tension forces proximal to holes or in widerstretches of material). In some forms, the surface of the material ofthe sealing portion that contacts the patient's face may have lowfriction characteristics (e.g., a low friction finish), which mayadvantageously improve compliance of the material with the patient'sface while also improving patient comfort.

The textile membrane may also comprise at least one layer that exhibitssubstantially air-impermeable characteristics, while maintaining theresilient stretch characteristics necessary for comfort and minimalpressure points. That is, a membrane layer or laminate film layer (e.g.,a polymer such as silicone, polyurethane, thermoplastic polyurethane(TPU), polyester, nylon, etc.) may be applied to the textile material toprovide a substantially air-tight material. In an alternative example,the fibers of a textile may be tightly weaved to create a substantiallyair impermeable material.

In some forms, the textile material of the sealing portion may have athickness in the range of 0.275 or less (e.g., 0.275 to 0.075 mm, 0.275to 0.175 mm, 0.25 mm or less, 0.225 mm or less, 0.225 to 0.09 mm, 0.225to 0.095 mm, 0.225 mm, or 0.25 mm). The membrane layer may have athickness in the range of 0.03 to 0.01 mm (e.g., 0.015, 0.02 mm, or0.025 mm). The textile material of the sealing portion with the membranelayer may have an overall composite material thickness in the range of0.305 mm or less (e.g., 0.305 to 0.085 mm, 0.305 to 0.185 mm, 0.28 mm orless, 0.255 mm or less, 0.255 to 0.10 mm, 0.255 to 0.105 mm, 0.25 mm, or0.275 mm). In an example, a textile composite including a microfibertextile and a polyurethane film layer may have these dimensions.

In another example, the textile material of the sealing portion may havea thickness in the range of 0.15 mm to 0.5 mm (e.g., 0.2 mm to 0.4 mm,or 0.3 mm to 0.4 mm, or 0.25 mm, or 0.3 mm, or 0.4 mm). The membranelayer may have a thickness in the range of 0.03 mm to 0.125 mm (e.g.,0.05 mm to 0.1 mm, or 0.075 mm to 0.1 mm, or 0.05 mm to 0.075 mm, or0.05 mm, or 0.075 mm, or 0.1 mm). The textile material of the sealingportion with the membrane layer may have an overall composite materialthickness in the range of 0.18 mm to 0.625 mm (e.g., 0.25 mm to 0.6 mm,or 0.25 mm to 0.5 mm, or 0.3 mm to 0.5 mm, or 0.35 mm to 0.45 mm, or 0.3mm, or 0.35 mm, or 0.4 mm, or 0.45 mm, or 0.5 mm). In an example, atextile composite including a nylon or nylon and polyester mix textileand a silicone film layer may have these dimensions.

Tensile forces may also be transferred to the sealing portion as aresult of the stiffness and resilient properties of the supportstructure. The support structure may be formed from a variety ofmaterials, including silicone, foam (e.g., polyurethane foam),polyurethane solid material, thermoplastic elastomers (TPE) (e.g.,thermoplastic polyurethane (TPU)), and suitable plastic materials. Thesupport structure may be configured so as to create a number ofdifferent cushion configurations, including a single air assistedsealing portion (e.g., textile membrane) and a sealing portion withunderlying cushion support layer(s) such as a double air assistedsealing portion (e.g., dual textile membranes), a sealing portion withcompression support (e.g., open cell foam, polyurethane foam, gel), asealing portion with TPU, TPE or silicone support, or a double airassisted sealing portion with additional support (e.g., dual textilemembranes wherein the inner membrane has a foam laminate layer (e.g.,open cell, polyurethane) or a TPU, TPE, polyurethane or silicone moldedlayer thereon).

The underlying cushion layer(s) may assist in optimizing the sealingportion contact surface area with the patient's face. Further, inexamples where the sealing portion is constructed from a breathablematerial (e.g., a breathable textile), the underlying cushion layer(s)may provide sufficient contact area behind the sealing portion toadequately seal the sealing portion against the patient's face andprevent leakage.

In use, engagement of the patient's face 1000 with the sealing portion10130 will create a temporary strain force that attempts to pull thewalls of the support structure 10120 toward one another, as shown inFIG. 81. The support structure 10120 will respond to the strain forcewith an outwardly pulling reaction force. The reaction force transfersmore tension to the sealing portion 10130 by preferentially stretchingthe more compliant sealing portion which creates a resultant springforce in the sealing portion that is exerted on the patient's face.

In some examples, the support structure may comprise a seal biasingportion that utilizes the internal air pressure to dynamically supportthe support structure and sealing portion. This may advantageouslyprovide further support of the sealing portion when under dynamic loads(e.g., tube drag).

The air pressure within the cavity and acting against the inside surfaceof the sealing portion may also ensure that a surface of the textilemembrane without wrinkles, creases, buckles or folds (e.g., by creatingtension in the sealing portion) in presented to the patient's face suchthat the sealing portion may substantially fill depressed contours of apatient's face (e.g., around the sides of the nose). This may enable thecompliant sealing portion to form a larger seal contact area on thepatient's face. The tension in the sealing portion created by the airpressure within the cavity may also be advantageous in providing acontinuous seal even when the mask is partially displaced with anoptimal positioning on the patient's face, as the sealing portion maypartially inflate (i.e., a “hovercraft effect”) due to the counter-forcefrom the internal air pressure.

In examples where the textile membrane is not under constant tension(and e.g., also non-elastic), the sealing portion may still bemaintained in sealing contact with the patient's face by the airpressure within the cavity and form an improved air assisted seal withthe patient's face that conforms dynamically to alterations/movements(i.e., “hovercraft effect”) due to the sealing portion being thinner andhaving a lower structural stiffness than the support structure.

The sealing portion may be integrated with the support structure bymolding or otherwise attaching the sealing portion to the inner edge ofthe support structure. Thus, for example, an outer perimeter of thesealing portion may be attached to the inner edge of the supportstructure such that the sealing portion extends radially inwardly of theseal-forming structure beyond or to a further extent than the supportstructure. The inner edge of the support structure may be curved suchthat the sealing portion may be slightly angled inwardly toward the maskinterior. By attaching the sealing portion along the inner edge of thesupport structure, the sealing portion does not need to be folded or cutto blend around the corners of the support structure. This mayadvantageously reduce the occurrence of protruding folds or wrinkles inthe sealing portion, which may cause leakage, thereby improving theperformance of the seal.

As described earlier, the seal-forming structure may be removablyconnected or fixedly attached to the plenum chamber. In some forms, thesealing portion may have a removable or modular structure. For example,the sealing portion may be attached to a supporting frame structurealong its perimeter. The supporting frame may be removably attached as amodule to the support structure. The sealing portion may be attached tothe supporting frame so as to reduce the occurrence of protruding foldsor wrinkles in the textile surface. The modular arrangement may alsosubstantially simplify the manufacturing of the sealing portion (e.g.,textile sealing portion) as all the complex bonding can be done in asimple unstressed state. While the sealing portion may be treated tohave substantially self-cleaning properties, the use of a modularsealing portion may also provide a cheaper and more hygienicalternative.

The supporting frame may be pre-formed to have a flat orthree-dimensional shape such as an arc so as to impart a curved shape tothe sealing portion. The supporting frame may form an air-tight sealwith the support structure. In some examples, the supporting frame mayengage the support structure by connectors (e.g., male/female locationpins/holes, tongue and groove).

The sealing portion may have underlying cushion support layer(s) (e.g.,second, third or more cushion layers) incorporated therein. Theunderlying cushion layer(s) may provide additional flexibility and allowthe cushion to be suitable for use by most patient faces (e.g., one sizefits most). For example, the sealing portion may be structured as adouble air assisted sealing portion (e.g., dual textile membranes), asealing portion with compression support layer(s) (e.g., open cell foam,polyurethane foam, gel), a sealing portion with TPU, TPE or siliconesupport layer(s), or a double air assisted sealing portion withadditional support layer(s) (e.g., dual textile membranes wherein theinner membrane has a foam laminate layer (e.g., open cell, polyurethane)or a TPU, TPE, polyurethane or silicone molded layer thereon).

In some examples, the support layers may be supported by a rigidstructure such as plastic, e.g., polypropylene (PP), polycarbonate (PC),polyamide (PA), or polyethylene terephthalate (PET).

In some examples, 3D printing of the sealing portion, support layersand/or support structure as a “skeleton” may reduce the thickness of thestructure and thus the weight of the mask. Also, different layers of themask could be printed with different rigidity, hardness, or thickness.For example, “skeleton” sections may be formed using silicone, foam(e.g., polyurethane foam), polyurethane (e.g., polyurethane solidmaterial), or any suitable plastic material. In some examples, a sealbiasing portion may be formed that may provide dynamic support in use.

5.3.5.1 Seal Biasing Portion

FIGS. 118A to 128 show a range of different cushion assemblies depictingvarious seal biasing portions 32160 and/or connector gussets 32172 inaccordance with examples of the disclosed technology. The cushionassemblies are nasal cradle cushions intended to seal against at leastthe underside of the patient's nose, as described above for example inFIGS. 5-37 and may include any of the features of any nasal cushiondescribed in another example in this disclosure. For example, thecushion assemblies disclosed in this section may include underlyingcushions as described in other nasal cradle examples. As those skilledin the art will understand, the seal biasing portion 32160 may also beemployed in other cushion types, such as the other cushion typesdescribed in this disclosure (e.g., nasal, oro-nasal, full face, etc.).In areas where the sealing portion 32130 is attached directly to theseal biasing portion 32160, the sealing portion may have its inner edgeattached (e.g., molded) to the seal biasing portion in the same orsimilar manner as described elsewhere in this disclosure regarding theconnection of the sealing portion to the support structure.

As described above, the plenum chamber 3200 may be constructed from arelatively rigid material as compared to the seal-forming structure32100.

Alternatively, the plenum chamber 3200 may be constructed from aflexible material (e.g., silicone) and may be formed as a one-piecestructure with the support structure 32120 (e.g., the seal-formingstructure may be an extension of the plenum chamber or formed as a partof the plenum chamber such that the plenum chamber encompasses theseal-forming structure, as described above). As an example of such, theplenum chamber 3200 may extend seamlessly into the seal-formingstructure 32120, as shown in FIG. 128.

In some examples, the support structure 32120 and the sealing portion32130 may comprise textile. In other examples, the sealing portion 32120may not comprise textile (e.g., may comprise silicone). The plenumchamber connectors 3204 described in this section may be identical orsimilar to the plenum chamber connectors 3204 described elsewhere inthis disclosure.

As described herein, specific manufacturing processes may be required inorder to produce rounded or curved (e.g., dome-shaped) portions of atextile sealing portion having curvature in two or more directions. Suchcurved portions may allow the patient's face to sink into the textilemembrane to better conform to facial contours and also tend to provide amore dynamic seal that can withstand at least some external forces. Adynamic seal may be considered, for example, as a seal that maintainssealing contact with the patient's face while the cushion body (e.g.,plenum chamber, support structure) and patient's face move relative toone another. As such, a seal biasing portion 32160 that will enhance thedynamic sealing capabilities of a textile sealing portion and extend thereach of the sealing portion without the need for such specificmanufacturing processes, may be particularly beneficial in conjunctionwith a textile membrane. Even if such rounded portions of a textilesealing portion are provided, the seal biasing portion 32160 may stillfurther enhance the sealing capabilities of the textile membrane.

The reach of the sealing portion 32130 may be considered, for example,as a potential maximum distance between the plenum chamber 3200 and/oran anterior side of the cushion assembly and the sealing portion 32130.That is, the reach of the sealing portion may be considered, forexample, as a potential maximum distance the cushion assembly (e.g.,side wall including seal biasing portion 32160) projects the sealingportion 32130 from the plenum chamber and/or the anterior side of thecushion assembly. When the cavity is not pressurized, the sealingportion 32130 has a certain potential maximum distance from the plenumchamber and/or anterior side of the cushion. As the cavity ispressurized, the seal biasing portion 32160 inflates and the potentialmaximum distance changes, possibly depending on the level ofpressurization in the cavity. Thus, when the cavity in the cushionassembly is pressurized in use and the seal biasing portion 32160 isinflated thereby allowing for a greater potential maximum distancebetween the plenum chamber 3200 and/or an anterior side of the cushionassembly and the sealing portion, the reach of the sealing portion isextended.

It is noted that, at a first level of pressurization sufficient to atleast partially inflate the seal biasing portion 32160, the potentialmaximum distance will be greater than when the cavity is not pressurizedbut may be less than a potential maximum distance at higherpressurizations, since the first level may not be sufficient to fullyextend the seal biasing portion 32160 (e.g., thick material). It isfurther noted that, even at a pressurization level sufficient to fullyextend the seal biasing portion 32160, some slack may remain in the sealbiasing portion due to headgear fitting, nose size, etc.

In use, when the seal biasing portion 32160 is inflated, the sealingportion 32130 may move or travel in a direction towards at least aportion of the patient's face. This may facilitate the sealing portionin effecting a seal with areas of complex geometry (e.g., nasal alar andsubalare). If the sealing portion 32130 is not moved a maximum distance,some slack may remain in the seal biasing portion 32160 thereby allowingthe seal biasing portion to absorb dynamic forces exerted on the cushionassembly while the sealing portion maintains sealing contact with thepatient's face.

The seal-forming structure 32100 may include structures (e.g., the sealbiasing portion 32160) that provide a pressure assisted biasingmechanism that enhances the sealing capabilities of the sealing portion(e.g., textile membrane). In some forms, the seal biasing portion 32160may be arranged such that, when activated under internal pressure, anactive region 32140 of the sealing portion may positively engage with acorresponding region of the patient's face. As shown in FIGS. 118A to127, the seal biasing portion 32160 may be configured to inflate toextend the reach of the sealing portion 32130, thereby allowing 1) thesealing portion to better accommodate a ranges of nose sizes (e.g.,wider noses and thinner noses) since inflation of the seal biasingportion allows the sealing portion to travel to reach and seal againstthinner noses; and 2) the sealing portion to actively and positivelyengaging with regions of the patient's face that may otherwise bedifficult to seal against without creating discomfort (e.g., byovertightening the headgear which can cause occlusion of the airwaysprior to the introduction of pressurised air).

For example, the seal biasing portion 32160 (e.g., FIG. 119A) may extendthe reach of active regions 32140 of the sealing portion (e.g., inlateral regions 32136 of the cushion assembly arranged to facilitatesealing around the nasal alar and/or the subalare). As described furtherbelow, a non-active region 32142 of the sealing portion (e.g., at acentral (i.e., medial) region 32138) may represent a region of thesealing portion where the seal biasing portion 32160 is not present,does not affect the reach of the sealing portion and/or is present andaffects the reach of the sealing portion to a lesser degree than in theactive regions 32140 of the sealing portion. The central region may beconfigured to seal with the patient's subnasale and columella to a pointat or above the pronasale but below the nasal bridge (however, in someexamples, the sealing portion may seal below the pronasale). In anexample (e.g., FIG. 119B), a non-active region 32142 may work inconjunction with the active regions 32140 to create a cradling orpinching action that better seals at the nasal alar and subalare. Thus,the seal biasing portion 32160 may improve dynamic stability of theseal-forming structure and may further improve sealing in hard to reachareas, thereby advantageously generating a more efficient and robustseal with the patient's face.

During therapy, the cavity within the cushion assembly is pressurizedwhich in turn inflates the seal-forming structure 32100, thereby forcingthe seal biasing portion 32160 to resiliently extend in the manner of apneumatic spring such that the sealing portion 32130 may move in aposterior direction (or in a posterior direction and a superiordirection (e.g., a posterosuperior direction)) (i.e., towards thepatient's face). The seal biasing portion 32160 may remain inflated(i.e., in a biased state) during the course of therapy by the presenceof pressurized air in the cavity, thereby effectively forming an airassisted spring within the cushion assembly (e.g., within the sealforming structure).

However, when the cushion assembly is configured to effect the cradlingor pinching action described above (e.g., FIG. 119B), the seal biasingportion 32160 may cause the lateral regions 32136 to inflate or expandradially inwardly (e.g., in a left-right direction) toward a center ofthe cushion assembly to press the sealing portion against the sides ofthe nose (e.g., nasal alar). To facilitate such cradling or pinchingaction, at least a portion of the central region 32138 may function as ahinge, pivot, and/or bending/flexing area. The cradling or pinchingaction of the seal biasing portion 32160 when inflated may cause thesealing portion 32130 to move in a direction having components in aposterior direction and a superior direction (e.g., a posterosuperiordirection) as well as a left-right direction (in other words, aposterosuperior direction and a left-right direction).

Additionally, it is noted that the seal-forming structure 32100 isarranged such that the sealing portion 32130 may have a saddle shape,e.g., concave curvature in the left-right direction and convex curvaturein the inferior-superior direction, to accommodate the underside of apatient's nose (e.g., as shown in FIGS. 119A to 127). Due to the saddleshape, the sealing portion may also tend to cradle the patient's nosesimply by being inflated towards the patient's face under pressurizationin the cavity.

By increasing pressure within the cavity, the seal biasing portion 32160may be inflated to a greater extent (up to a maximum extension length),thereby increasing the force with which the active regions 32140 of thesealing portion engage the patient's face. In this way, the seal biasingportion 32160 may actively extend the patient contacting portion of theseal forming structure 3100. This may increase the range of facialprofiles that may be accommodated with a single sized patient interface.As mentioned above, the seal biasing portion 32160 may also improveefficiency of the seal formed between the sealing portion 32130 and thepatient's face by extending the reach of the sealing portion and also bydecoupling external forces. Further, provision of the seal biasingportion 32160 may reduce instances of occlusion prior to theintroduction of pressurized air during therapy (which sometimes occurs,for example, through overtightening of the headgear, etc., in an effortto create a seal with hard to reach areas of the patient's face),thereby improving comfort for the patient.

Referring to FIG. 118A, when a patient with wider anthropomorphicfeatures (e.g. wider nose) engages the sealing portion 32130, the activeregions of the sealing portion may expand outwardly away from each other(i.e., splay apart) so as to accommodate for, and seal against, thepatient's features. Due to pressurization in the cavity, the sealbiasing portion 32160 may be under compression thereby applying a slightspring force against the wider nose that may enhance the seal withoutcausing discomfort. In contrast, as shown in FIG. 118B, when the patientinterface is worn by a patient with narrower anthropomorphic features(e.g. narrower/thinner nose), the active regions may bias inwardlytoward one another (e.g., cradle, clamp or pinch) upon pressurization ofthe cavity in the cushion assembly during use, so as to accommodate for,and seal against, the particular patient's unique facial features. Thatis, due to pressurization in the cavity, the seal biasing portion 32160may inflate thus causing the sealing portion 32130 to extend therebycontacting and sealing against the surfaces of thinner noses.

In some forms, when activated in use, the seal biasing portion 32160 maymechanically support the active regions 32140 of the sealing portion.This may increase the dynamic stability of the seal formed with thepatient's face. The seal biasing portion 32160 may be configured (e.g.,by being formed of a relatively thin material (e.g., silicone)) toreadily expand under pressurization. In such an example, the sealbiasing portion may have a thickness that is thinner than adjacentportions of the support structure and/or plenum chamber.

In examples, the geometry (e.g., shape and thickness) and materialproperties (e.g., stretch characteristics of the textile membrane) ofthe seal forming structure 32100 may be adapted to complement theability of the seal biasing portion 32160 to resiliently extend underpressurization. The combined resulting effect of the pneumatic springand the mechanical support properties of the seal biasing portion 32160may improve dynamic stability and support of the sealing portion 32130in maintaining sealing contact against the patient's face. That is, theseal biasing portion 32160 may be configured to maintain contact betweenthe sealing portion 32130 and the patient's face when the cushionassembly is moved dynamically either a relatively small distance (e.g.,2-7 mm, 3-5 mm) away from the patient's face, or when shifted laterallyacross the patient's face.

For example, the cushion assembly may experience a force from a pillowwhen a patient is sleeping on his or her side. This dynamic force maycause the cushion assembly to move away from or across the patient'sface. The seal biasing portion 32160 may work in combination with thegeometry and material properties of the seal forming structure 32100 toassist in absorbing such dynamic forces to maintain continuous contact(and thus a continuous seal) against the patient's face, therebycreating a “decoupling effect,” whereby the dynamic forces may bedecoupled from the sealing portion. That is, the seal biasing portion32160 provides for decoupled movement between the sealing portion 32130and the remaining portions (e.g., plenum chamber, support structure,etc.) of the cushion assembly. For example, as shown in FIG. 118C, whena force is exerted on the cushion assembly tending to pull the cushionassembly away from the patient's face or shift the cushion assemblylaterally across the patient's face, the seal biasing region 32160 mayadjust (e.g., by allowing the seal-forming structure to shift laterally)so as to maintain pressurized contact of the sealing portion 32130against the patient's face.

In some forms, the seal biasing portion 32160 may provide a dynamicsupporting region that is activated upon pressurization of the cavityand is primarily designed to aid in supporting the sealing portion inmaintaining sealing engagement with the patient's face without applyingany significant biasing force to the sealing portion. In an example, thesealing portion 32130 may sufficiently sealingly engage the patient'sface when the seal biasing portion 32160 is activated while maintainingsome slack in the seal biasing portion to adjust to dynamic forcesexerted on the cushion assembly. In this way, the seal biasing portion32160 is designed primarily to absorb external loading applied to thepatient interface thereby decoupling the sealing portion from suchexternal forces.

In referring to FIGS. 118A to 127, the seal biasing portion 32160 may beformed of a flexible material (e.g., silicone). The seal biasing portion32160 may be formed from the same material as the support structure32120 (e.g., including any materials described in this disclosure assuitable for the support structure). Alternatively, the seal biasingportion 32160 may comprise a textile (e.g., the same textile materialincluded in or the same composite material used as the textilemembrane). As mentioned above, the seal biasing portion is flexible soas to inflate when the cavity within the cushion assembly is pressurizedduring use. To facilitate inflation of the seal biasing portion 32160,the wall structure of the seal biasing portion may be thinner (orotherwise less rigid and therefore more readily inflatable) thanadjacent portions of the support structure 32120 and/or plenum chamber3200.

The sensitivity and efficiency of activation of the seal biasing portion32160 may be adjusted by adjusting the wall thickness of the sealbiasing portion. That is, a relatively thinner wall structure will bemore readily activated upon pressurization, whereas a relatively thickerwall structure will be less readily activated. In an example, the wallthickness of the seal biasing portion 32160 (e.g., silicone) may be inthe range of 0.2 mm to 0.6 mm (e.g., 0.3 mm to 0.5 mm); however, inother examples, the wall thickness could be thicker (e.g., 0.6 mm to 0.8mm) or thinner (e.g., 0.1 mm to 0.2 mm).

In some examples, the thickness of the seal biasing portion 32160 mayvary around the perimeter of the cushion assembly (e.g., the wallthickness in a first region (e.g., lateral regions 32136 of the cushionassembly) may be different than the wall thickness in a second region(e.g., central region 32138 of the cushion assembly). In an example, thewall thickness of the seal biasing portion 32160 at lateral regions32136 may be thinner than the wall thickness of the seal biasing portionin the central region 32138, to facilitate the sealing portion 32130 incradling or clamping the patient's nose at the subalare regions uponactivation of the seal biasing portion 32160 to create better sealingcontact with the nasal alar and hard to reach subalare region of thepatient's face.

In some examples, the seal biasing portion 32160 may be formed as anindented (or recessed) channel 32165 (e.g., FIG. 121) or externalprotrusion 32167 (e.g., FIG. 126) (or alternatively as a combination ofboth in the form of an accordion). When inflated, the seal biasingportion 32160 moves toward a straightened position and thereby extendsthe reach of the sealing portion 32130. The seal biasing portion 32160may extend along a marginal edge 32122 of the support structure 32120(e.g., FIGS. 120 and 121) in which case the seal biasing portion 32160may be connected directly to the sealing portion 32130. In anotherexample, the seal biasing portion 32160 may extend along a marginal edge32125 of the plenum chamber 3200 (e.g., FIGS. 122A to 123B) such thatthe support structure 32120 may be connected directly to the sealingportion 32130 (e.g., to provide more support to the sealing portion).Alternatively, the seal biasing portion 32160 may be disposed at anintermediate portion of the support structure.

In an example, the channel 32165 or protrusion 32167 may form a crease.In some forms, the channel 32165 may have a saddle shape (e.g., FIG.121) and the protrusion 32167 may have a dome shape (e.g., FIG. 126) (ora plurality of saddle and dome shapes may be present when channels andprotrusions are used in combination).

In examples, such as shown in FIGS. 121, 123A, 123B, and 125-127, theseal biasing portion 32160 may extend around the entire perimeter of thecushion assembly.

The reach of the sealing portion 32130 may be adjusted by adjusting thesize of the seal biasing portion (e.g., the depth of the channel 32165or extent of the protrusion 32167). That is, a deeper channel or largerprotrusion may provide greater reach, whereas a shallower channel orsmaller protrusion may provide less reach. Further, the depth of thechannel 32165 and/or extent of the protrusion 32167 may vary around theperimeter of the cushion assembly. In an example, a relatively deeperchannel 32165 or larger protrusion 32167 may be provided at lateralregions 32136 of the cushion assembly, and a relatively shallowerchannel or smaller protrusion may be formed in a central region 32138 ofthe cushion assembly (e.g., FIG. 121). This may allow the sealingportion 32130 to create a pinching or cradling action to snugly engagethe patient's nose and to more effectively seal at the nasal alar andhard to reach subalare portions of the patient's face. In such anexample, at least a portion of the central region 32138 may function asa hinge, pivot, and/or bending/flexing area.

Additionally, as shown in FIGS. 121 to 123B, the seal biasing portion32160 may taper from a larger (e.g., deeper channel) seal biasingportion 32160 to a smaller (e.g., shallower channel) seal biasingportion, or vice versa, as the seal biasing portion extends around theperimeter of the cushion assembly. That is, as shown for example inFIGS. 122A to 123B, the seal biasing portion 32160 may taper from adeeper channel in lateral regions 32136 to a shallower channel in oradjacent to the central region 32138. Those skilled in the art will alsounderstand that the depth of the channel 32165 or protrusion 32167 maybe uniform around the entire perimeter or a portion of the perimeter ofthe cushion assembly.

Further, it is noted that the seal biasing portion 32160 may be omittedin certain regions of the cushion assembly to vary the reach of thesealing portion 32130 around the perimeter of the cushion assembly, asdesired. For example, as shown in FIGS. 119A to 120, 122A and 122B, theseal biasing portion 32160 may be omitted in at least a portion of thecentral region 32138. Thus, two seal biasing portions 32160 extendingrespectively partially around the perimeter of the cushion assembly areformed at the lateral regions 32136. This may also facilitate thepinching or cradling action of the cushion assembly to snugly engage thepatient's nose and to more effectively seal at the nasal alar and hardto reach subalare portions of the patient's face. In other examples, theseal biasing portion 32160 may be omitted in other regions of thecushion assembly such as the lateral regions 32136.

5.3.5.1.1 Top Surface Seal Biasing Portion Examples

Referring to FIGS. 119A to 119B, the seal biasing portion 32160 may bedisposed along a posterior patient-facing surface of the cushionassembly. The posterior patient-facing surface may be the surface orside of the cushion assembly directly opposed to the patient's face inuse and may include the sealing portion 32130, the seal biasing portion32160 and/or at least a portion of the support structure 32120. In theillustrated example, the seal biasing portion 32160 comprises at leastone fold, pleat, or undulation, e.g., a plurality of folds, pleats orundulations 32162 that form a substantially sinusoidal wave in crosssection, as shown in FIG. 119A-1. As shown in FIG. 119A, the sealbiasing portion 32160 may extend between the sealing portion 32130 andthe support structure 32120 such that a first end of the seal biasingportion is connected to the sealing portion and a second end of the sealbiasing portion is connected to the support structure. In areas wherethe sealing portion 32130 is attached to the seal biasing portion 32160,the sealing portion may have its inner edge attached (e.g., molded) tothe seal biasing portion.

Prior to pressurization of the cavity in the cushion assembly, thesealing portion 32130 may lie substantially flush, i.e., substantiallyeven or level, with a posterior-most portion (e.g., the posterior-facingfold, pleat or undulation 32162 shown in FIGS. 119A and 119A-1) of theseal biasing portion 32160. Upon pressurization of the cavity, thefolds, pleats or undulations 32162 may straighten (or move toward astraightened position) causing the sealing portion 32130 to extend ortelescope beyond the seal biasing portion 32160 and the other portionsof the posterior patient-facing surface in a direction towards at leasta portion of the patient's face (e.g., a direction having components inboth a posterosuperior direction and a left-right direction to cradle orwrap around the nasal alar under force exerted by pressure within thecavity of the cushion assembly).

In the illustrated example, the seal biasing portion 32160 extendsaround or is disposed in lateral regions 32136 of the cushion assemblyand is omitted in at least a portion of the central region 32138, thusproviding active regions 32140 of the sealing portion 32130 in thelateral regions 32136 and a non-active region of the sealing portion inat least a portion of the central region 32138 of the cushion assembly.

As described earlier, the seal biasing portion 32160 may extend thereach of the active regions 32140 when activated under pressurization,as shown in FIG. 119B. This may facilitate the pinching or cradlingaction of the cushion assembly (e.g., such that the sealing portion maywrap around or pinch/cradle the sides of the nasal alar and/or subalareportions of the patient's face). In another example, the pinching orcradling action may still be provided in a cushion assembly having aseal biasing portion 32160 in the central region 32138 (e.g., a sealbiasing portion extending around the entire perimeter (or encircling thesealing portion on the posterior patient-facing surface of the cushionassembly), provided such centrally located seal biasing portion issmaller than the seal biasing portion 32160 in the lateral regions32136. That is, the size of the seal biasing portion 32160 may vary indifferent regions around the cushion assembly. Further, as describedearlier, the seal biasing portion may also be uniform around the entireperimeter of the cushion assembly.

5.3.5.1.2 Side Surface Seal Biasing Portion Examples

Referring to FIGS. 120 to 128, the seal biasing portion 32160 may bedisposed on or as part of a side surface of the cushion assembly. Theside surface may be considered a side wall or a wall structure extendingaround an outer perimeter of the cushion assembly.

In the FIG. 120 example, the seal biasing portion 32160 is disposed on amarginal edge 32122 of the support structure 32120 such that the sealbiasing portion is connected directly to the sealing portion 32130. Insome examples, the portion of the seal biasing portion 32160 connectingto the sealing portion may be thicker than other portions of the sealbiasing portion to provide a desired level of support to the sealingportion. The support structure 32120 may be disposed between the plenumchamber 3200 and the seal biasing portion 32160.

In the FIG. 120 example, the seal biasing portion 32160 may be formed bybeing less rigid (e.g., thinner) than adjacent portions of the supportstructure 32120. Alternatively, the seal biasing portion 32160 may beformed by an indented channel (or recess), an external protrusion,folds, pleats or undulations.

As shown in FIG. 120, the seal biasing portion 32160 may extend aroundthe perimeter of the cushion assembly in lateral regions 32136 and maybe omitted in at least a portion of the central region 32138 of thecushion assembly. As previously described, this arrangement may extendthe reach of the active regions 32140 when activated underpressurization, which may facilitate the pinching or cradling action ofthe cushion assembly.

It is further noted that the seal biasing portion 32160 may extendthrough the lateral regions 32136 at an angle α (e.g., 30°-60°, 45°)with respect to horizontal (or a plane extending along an anterior sideof the cushion assembly). This may further position the sealing portion32130 to better cradle the underside of the patient's nose at the nasalalar by facilitating the sealing portion in extending inwardly in aleft-right direction when the seal biasing portion 32160 is activated inuse.

Referring to FIG. 121, the seal biasing portion 32160 may extend aroundthe entire perimeter of the cushion assembly. The seal biasing portion32160 may be disposed on a marginal edge 32122 of the support structure32120 such that the seal biasing portion is directly connected to thesealing portion 32130 (and the support structure 32120 connects the sealbiasing portion 32160 to the plenum chamber 3200). As described inreference to FIG. 120, in some examples, a thicker portion of the sealbiasing portion 32160 may be used to connect to the sealing portion32130.

The seal biasing portion 32160 may be formed as an indented channel32165 and a size (e.g., depth of the channel) of the seal biasingportion may taper as it extends along the perimeter of the cushionassembly. For example, the seal biasing portion 32160 may taper from alarger seal biasing portion in the lateral regions 32136 to a relativelysmaller seal biasing portion 32160 in the central region 32138, as shownin FIG. 121. This arrangement may extend the reach of the sealingportion 32130 in the lateral regions 32136 a greater distance than thereach of the sealing portion in or toward the central region 32138 isextended, thus facilitating the pinching or cradling action of thecushion assembly.

Turning to FIGS. 122A and 122B, the seal biasing portion 32160 may bedisposed on a marginal edge 32125 of the plenum chamber 3200, such thatthe support structure 32120 is disposed between the seal biasing portion32160 and the sealing portion 32130.

This arrangement having the support structure 32120 connected directlyto the sealing portion 32130 may provide more support to the sealingportion than the arrangement in the FIG. 120 example.

Similar to the FIG. 120 example, the seal biasing portion 32160 mayextend around the perimeter of the cushion assembly in lateral regions32136 and may be omitted in at least a portion of the central region32138 of the cushion assembly, as shown in FIGS. 122A and 122B. Theindented channel 32165 of the seal biasing portion 32160 may taper alongthe perimeter of the cushion assembly from a larger seal biasing portionin the lateral regions 32136 to a relatively smaller seal biasingportion 32160 toward the central region 32138. Further, as previouslydescribed, this seal biasing arrangement may extend the reach of theactive regions 32140 when activated under pressurization, which mayfacilitate the pinching or cradling action of the cushion assembly.

Referring to FIGS. 123A and 123B, the seal biasing portion 32160 may bedisposed on a marginal edge 32125 of the plenum chamber 3200, such thatthe support structure 32120 is disposed between the seal biasing portion32160 and the sealing portion 32130.

Similar to the FIG. 121 example, the seal biasing portion 32160 mayextend around the entire perimeter of the cushion assembly. The indentedchannel 32165 of the seal biasing portion 32160 may taper from a largerseal biasing portion in the lateral regions 32136 to a relativelysmaller seal biasing portion 32160 in the central region 32138, as shownin FIGS. 123A and 123B.

As previously described, this arrangement may extend the reach of thesealing portion 32130 in the lateral regions 32136 a greater distancethan the reach of the sealing portion at or toward the central region32138 is extended, thus facilitating the pinching or cradling action ofthe cushion assembly.

Turning to FIG. 124, a seal biasing portion 32160 is provided around thelateral regions 32136 of the cushion assembly and is omitted in at leasta portion of the central region 32138, thereby forming active regions32140 and a non-active region 32142. The seal biasing portion 32160 maycomprise a step 32164 and a wing 32166 that extend from the supportstructure 32120 in a vertical or posterior direction (or in a posteriorand superior direction (e.g. a posterosuperior direction) or in aposterosuperior direction and a left-right direction).

The step 32164 is connected directly to the support structure 32120. Thestep 32164 may extend from the support structure towards the patient'sface in use (e.g., in the posterosuperior direction and left-rightdirection) and may be angled with respect to the support structure. Thewing 32166 is connected directly to the step 32164. The wing 32166 maybe angled with respect to the step 32164, but extends further in adirection towards the patient's face (e.g., in the posterosuperiordirection and left-right direction). The angled arrangement of the step32164 and wing 32166 may create one or more folds, creases, pleats orbends in the material of the seal biasing portion 32160 that maystraighten (or move toward a straightened position) when inflated toextend the reach of the sealing portion 32160 and also form a decouplingarrangement to decouple external forces from the sealing portion.

The step 32164 and/or wing 32166 may comprise a relatively thin (orotherwise less rigid) material than the support structure 32120, suchthat the seal biasing portion 32160 may be activated upon pressurizationof the cavity within the cushion assembly.

As previously described, the arrangement of the seal biasing portion32160 in the lateral regions 32136 while being omitted in at least aportion of the central region 32138 may extend the reach of the lateralregions when activated under pressurization, which may facilitate thepinching or cradling action of the cushion assembly. It is also notedthat in other examples the seal biasing portion 32160 may extend aroundthe entire perimeter of the cushion assembly, and the size of the sealbiasing portion may vary around the perimeter (e.g., smaller (i.e.,relatively smaller step and/or wing) in central region and larger (i.e.,relatively larger step and/or wing) in lateral regions).

5.3.5.1.2.1 Stem Supported Seal Biasing Portion Examples

Referring to FIGS. 125 to 127, a cushion assembly has a sealing portion32130 that is connected to a plenum chamber via a support structure32120 that includes a stem 32135 that projects from the plenum chamber(not shown). A seal biasing portion 32160 may extend around a perimeterof the cushion assembly. The seal biasing portion is less rigid (e g,thinner) than adjacent portions of the support structure such that theseal biasing portion 32160 can extend the reach of the sealing portion32130 and also decouple the sealing portion from external forces appliedto the plenum chamber when the cavity within the cushion assembly ispressurized.

The seal biasing portion 32160 may support the sealing portion 32130 inthe way of a gimbal or ball joint, allowing movement and flexibility inmultiple directions. In this way, the seal biasing portion 32160 isconfigured to substantially isolate the sealing portion 32130 andprevent dynamic impacts that encounter the plenum chamber from affectingthe efficiency of the sealing portion in a manner similar to thatcommonly experienced by force absorbing suspension systems.

In an example, the seal biasing portion 32160 may be formed as anexternal protrusion 32167, as shown in FIG. 126. In the FIG. 127example, the seal biasing portion 32165 is formed as an indented (e.g.,recessed or concave) channel 32165. In other examples, the seal biasingportion 32160 may comprise a plurality of protrusions and/or channels.

The size of the seal biasing portion 32160 (e.g., larger or smallerchannel or protrusion) may vary around the perimeter of the cushionassembly and may be omitted in certain regions, as described above inother examples. The seal biasing portion 32160 may also taper around theperimeter of the cushion assembly as described above.

As previously described, an arrangement of the seal biasing portion32160 in the lateral regions 32136 while being omitted (or smaller) inat least a portion of the central region 32138 may extend the reach ofthe lateral regions when activated under pressurization, which mayfacilitate the pinching or cradling action of the cushion assembly.Further, it is noted that the seal-forming structure 32100 is arrangedsuch that the sealing portion 32130 has a saddle shape to accommodatethe underside of a patient's nose. As described above, due to the saddleshape, the sealing portion may also tend to cradle the patient's nosesimply by being inflated towards the patient's face under pressurizationin the cavity.

Further, the size of the seal biasing portion 32160 may be selected inaccordance with a stem 32135 length. For example, a larger seal biasingportion 32160 may allow for a shorter stem 32135 since the seal biasingportion will allow the sealing portion 32130 to sufficiently reach thesealing area of the patient when activated.

5.3.5.1.3 Connector Gusset

As shown in FIG. 128, an air tube connection portion of the cushionassembly includes an inlet port 32170 configured to receive a flow ofair from an air supply tube (e.g., an elbow assembly connected to an airsupply tube as those skilled in the art will understand). For example,the inlet port 32170 may be formed in an anterior side of the plenumchamber, as shown in FIG. 128. The plenum chamber may include connectorstructure to connect to air supply tube (e.g., via the elbow assembly).

The air tube connection portion may include a connector gusset 32172configured to absorb dynamic forces (e.g., external forces exerted onthe air supply tube, i.e., tube drag). The connector gusset 32172 maycomprise one or more folds, pleats and/or undulations formed along ananterior wall portion of the plenum chamber adjacent the inlet port. Asshown in FIG. 128, the connector gusset surrounds the inlet port, suchthat the folds, pleats or undulations form a circular arrangementextending around the entire perimeter of the plenum chamber adjacent theinlet port thereby essentially being coaxial with the inlet port. Inother examples, the connector gusset 32172 may not extend entirelyaround the cushion assembly and may be interrupted (e.g., the connectorgusset may have diametrically opposed portions extending around theinlet port that are interrupted by sections without folds, pleats orundulations). In an example, the connector gusset 32172 could have anaccordion configuration.

The connector gusset 32172 is structured to absorb dynamic forcesexerted on the supply tube and decouple the forces from the seal-formingstructure (e.g., sealing portion) thereby enhancing the dynamicstability of the sealing portion 32130 in use.

5.3.5.2 Textile Membrane

In accordance with an example of the disclosed technology, thesealing-forming structure may include a textile membrane comprising atextile material. The textile material may have an airtightmembrane/film or layer coated or otherwise applied thereto to create anair-holding textile composite. The textile composite may be cut (e.g.,die cut, ultrasonic, laser, or RF) to a desired shape and then attachedto the support structure. The resulting textile sealing portion (ortextile membrane) may be attached to the support structure (e.g.,silicone, TPE), for example, by overmolding or injection molding. Inanother example, the textile sealing portion may be thermo-welded at itsedges (outer perimeter) onto the support structure material (e.g.,silicone, TPE).

A textile is a material including at least one natural or artificialfiber (e.g., yarn or thread). The fiber may be a filament (mono orpoly), a strand, a thread or twine. The fiber(s) may includeanimal-based material such as wool or silk, plant-based material such aslinen and cotton, and synthetic material such as polyester and rayon.Textiles may be formed by various techniques, such as weaving, knitting,crocheting, knotting, tatting, bonding, felting, tufting, or braiding,and may include, for example, woven and nonwoven materials, e.g., byintertwining or interlacing one or more of the fibers.

In an example, the textile material is a knitted material. A knittedmaterial may be preferable as it provides the textile with elasticity(e.g., stretchiness), particularly in comparison with woven materials.This may be advantageous in providing comfort to the patient, asdescribed below. The elasticity may be in all directions (e.g., four-waystretch/elasticity, e.g., substantially equal elasticity in alldirections), and at least in the lateral left-right direction of thetextile membrane. The textile material may have a weft knit structure ora warp knit structure, for example. A weft knit structure may be moredesirable as the elasticity of weft knit textiles is higher than theelasticity of warp knit textiles.

FIG. 113 illustrates the wale 70 of a weft knit fabric, or the directionthat the loops of one thread join to a loop of another thread. Thecourse 80, or the direction of the loops from a single thread is shownin FIG. 114. FIG. 115 illustrates a basic closed loop warp knit 90 inwhich the wales and courses running parallel to one another. FIG. 116illustrates a weft knit 100 in which the wales 70 run perpendicular tothe course 80.

5.3.5.2.1 Manufacturing

In an example, an overmolding process may be used to construct aseal-forming structure having a, e.g., flexible, support structure(e.g., silicone) attached to a textile membrane.

As shown in FIG. 117, in step 10, an airtight textile composite may beformed by combining a textile material with an impermeable material. Aheat process may be used to attach the impermeable layer to the textilematerial, as shown in FIG. 78 for example. The textile composite mayhave a flat shape (e.g., sheet-shaped).

In step 12, the textile composite may be cut to a desired shapeaccording to a particular cushion assembly to be used.

In step 14, the support structure (e.g., silicone) may be overmoldedonto the textile composite to form a seal-forming structure with atextile membrane. The textile composite may be held in place by a vacuumso as to have a non-flat predefined shape during the overmoldingprocess. That is, the flat textile composite may be overmolded with thesupport structure so as to impart curvature to the textile compositethereby forming a textile membrane that may have curvature withoutwrinkles, folds, creases and/or buckles being formed in the textilemembrane. As can be seen in FIG. 33-1, the textile membrane may extendalong the curve 35 from the anterior side of the seal-forming structureto the posterior side of the seal-forming structure. In an example, asshown in FIG. 33-1, the support structure and textile membrane may bothhave a radius of curvature (e.g., the same or similar radius ofcurvature) along the curve 35. The textile membrane may have apredefined curvature imparted thereto such that a portion of the textilemembrane not directly supported by the support structure extends alongthe curve 35 (FIGS. 33-2 to 33-4). As discussed earlier, the textilemembrane may also have, for example, curvature in the way of dome andsaddle shapes in other regions of the textile membrane. The textilemembrane may have a concave curved profile from one lateral side (right)to an opposing lateral side (left) (e.g., positive curvature in aleft-right direction) that may be imparted during the overmoldingprocess and maintained by connection to the support structure (see FIGS.11-17, 23-27, and 33-37 for example). In another example, the textilemembrane may have negative curvature in an inferior-superior directionthat may be imparted during the overmolding process and maintained byconnection to the support structure (see FIGS. 18-22 for example).

The support structure may be molded onto the textile composite such thatthe outer surface of the seal-forming structure is smooth and seamlessin the transition from the support structure to the textile membrane(see FIG. 33-4). The support structure may bond to the impermeablematerial of the textile membrane. While the outer surface of theseal-forming structure may be smooth and seamless, a step may be presenton the inner surface of the seal-forming structure where the thicknessof the support structure is different (e.g., greater) than the thicknessof the impermeable layer.

The overmolding process forms the seal-forming structure withoutcreating any wrinkles, folds, creases and/or buckles in the textilemembrane while also imparting curvature to the textile membrane.

5.3.5.2.2 Textile Membrane Examples

Below are example properties and structural arrangements of the textilecomposite used as the material for the textile membrane.

5.3.5.2.2.1 Textile Composite Structure

Various combinations of textile materials and membrane/film layers maybe used. In an example, a three-layer arrangement including athermoplastic polyurethane (TPU) film disposed between two textilelayers (e.g., nylon, nylon and polyester mix, nylon and spandex mix,polyester and spandex mix, or nylon/polyester/spandex mix) is used. Theadditional textile layer is needed to protect the TPU film from breaking(e.g., during cleaning).

In another example, a two-layer arrangement including a textile (e.g.,nylon, nylon and polyester mix, nylon and spandex mix, polyester andspandex mix, or nylon/polyester/spandex mix) having a silicone layer(e.g., coated thereon) is used. This composite material may be lessexpensive than the three-layer arrangement discussed above, since onlyone layer of textile is needed.

In another example, a textile material (e.g., a microfiber orpolyurethane material) may be coated with a polyurethane film to form atwo-layer arrangement.

5.3.5.2.2.2 Textile Material

As described above, a number of textile materials maybe used to form thesealing portion, such as nylon, polyester, spandex, nylon and polyestermix, nylon and spandex mix, polyester and spandex mix,nylon/polyester/spandex mix, microfiber or polyurethane.

In an example, a nylon material is used. Nylon may provide comfortbenefits to the patient as it is softer than polyester. Nylon is alsomore durable than polyester and therefore provides enhancements in lifespan and durability. Further, as compared to polyester, nylon has ahigher melt temperature and therefore is able to withstand highertemperature manufacturing conditions.

In another example, a nylon and polyester mix material is used. Thismaterial may be more desirable as it absorbs moisture less readily dueto the addition of polyester and therefore reduces irritation to thepatient. The nylon and polyester mix is also less expensive than nylon.

5.3.5.2.2.3 Textile Material Thickness

In an example, the textile material of the sealing portion may have athickness in the range of 0.15 mm to 0.5 mm (e.g., 0.2 mm to 0.4 mm, or0.3 mm to 0.4 mm, or 0.25 mm, or 0.3 mm, or 0.4 mm). Such a thicknessmay be suitable for a nylon material or nylon and polyester mixmaterial.

In another example, the textile material of the sealing portion may havea thickness in the range of 0.275 or less (e.g., 0.275 to 0.075 mm,0.275 to 0.175 mm, 0.25 mm or less, 0.225 mm or less, 0.225 to 0.09 mm,0.225 to 0.095 mm, 0.225 mm, or 0.25 mm). Such a thickness may besuitable for a microfiber textile material or a polyurethane textilematerial.

5.3.5.2.2.4 Air Impermeable Layer Thickness

In examples where silicone is used as the membrane/film layer, thesilicone may have a thickness in the range of 0.03 mm to 0.125 mm (e.g.,0.05 mm, 0.05 mm to 0.1 mm, or 0.05 mm to 0.075 mm, or 0.075 mm to 0.1mm, or 0.1 mm). A thinner silicone layer (e.g., 0.05 mm) may be moredesirable as it provides a lighter weight product and also provides morestretch than thicker silicone layers (e.g., 0.1 mm). Thicker siliconelayers (e.g., 0.1 mm), however, are more durable than thinner layers(e.g., 0.05 mm).

In another example, where a polyurethane film is used as the membranelayer, the polyurethane film may have a thickness in the range of 0.03to 0.01 mm (e.g., 0.015, 0.02 mm, or 0.025 mm).

5.3.5.2.2.5 Textile Composite Total Thickness

In examples where a textile material is coated with a siliconemembrane/film layer, the overall composite material may have a thicknessin the range of 0.18 mm to 0.625 mm (e.g., 0.25 mm to 0.6 mm, or 0.25 mmto 0.5 mm, or 0.3 mm to 0.5 mm, or 0.35 mm to 0.45 mm, or 0.3 mm, or0.35 mm, or 0.4 mm, or 0.45 mm, or 0.5 mm).

Thicker textile membrane thicknesses (e.g., 0.5 mm) may be sturdier andprovide a less flimsy impress. These textile membranes may be easier tohandle during manufacturing as they are less likely to flop around.

A middle range thickness (e.g., 0.35 mm to 0.45 mm) may provide aflexible, lightweight structure that is relatively easy to handle duringmanufacturing and may provide more comfort to the patient than a thickertextile membranes.

A thinner textile membrane may provide a very lightweight structure thatprovides a soft comfortable touch to the patient, but may provide lessdurability than thicker textile membranes.

In examples where a textile material is coated with polyurethane film,the overall composite material may have a thickness in the range of0.305 mm or less (e.g., 0.305 to 0.085 mm, 0.305 to 0.185 mm, 0.28 mm orless, 0.255 mm or less, 0.255 to 0.10 mm, 0.255 to 0.105 mm, 0.25 mm, or0.275 mm).

5.3.5.2.2.6 Knit Structure

The textile material of the textile membrane may have a weft knitstructure or, alternatively, a warp knit structure, for example. A weftknit textile may be more desirable as this may provide the material withhigher elasticity as compared to a warp knit textiles. This may beadvantageous as it may provide more comfort to the patient by stretchingas the patient's face engages the textile membrane thereby reducing theforce applied to the patient's face by the textile membrane.

In an example, the weft direction (direction of the course 80) mayextend in the nose width direction of the textile membrane, since theweft direction may have greater elasticity or stretch. Alternatively,the weft direction may extend in the nose length direction(superior-inferior direction).

Additionally, weft knitting is more suitable for producing relativelythin materials, such as discloses herein. Also, weft knitting isgenerally less cost prohibitive than warp knitting.

However, in some examples, warp knitting may be desirable as it providesless shrinkage than weft knit materials.

5.3.5.2.2.7 Knitting Machine

A weft knit textile material may have a single jersey knit structurewhich provides a technical face and a technical back that have differentappearances. A single jersey knit may be formed by one set of needlesand may provide knit stitches on the technical face (front) and purlstitches on the technical back. In an example, the technical face mayform the outer surface of the textile membrane and the air impermeablemembrane may be attached to the technical back. Alternatively, thetechnical face could be oriented towards an inner surface of the textilemembrane and have the membrane attached thereto.

In an example where the textile membrane includes an air impermeablemembrane sandwiched between two textile layers, the technical face ofeach textile material may form the exposed surfaces of the textilemembrane.

5.3.5.2.2.8 Textile Weight

The textile material may have a weight in the range of 95 grams persquare meter (gsm) to 130 gsm (e.g., 105 gsm to 120 gsm, or 110 gsm to115 gsm, or 105 gsm, or 110 gsm, or 120 gsm). A heavier weight textile(e.g., 120 gsm) may provide a desirable comfortable textile feel evenafter being coated with a laminate layer due to theweightiness/thickness of the textile. A lighter weight textile (e.g.,105 gsm) may be desirable as it provides a lighter product.

5.3.5.2.2.9 Machine Gauge

The machine gauge (i.e., the number of stitches per inch) of the textilematerial may vary. For example, the machine gauge may be in the range of35 GG to 70 GG (e.g., 44 GG to 60 GG, or 50 GG to 55 GG, or 55 GG to 60GG, or 44 GG, or 50 GG, or 55 GG, or 60 GG).

Using relatively larger gauge materials (e.g., 44 GG) may be desirableas this provides greater options for melange materials. However, a finergauge materials (e.g., 60 GG) may be desirable as this softer materialswhich may enhance patient comfort.

5.3.5.2.2.10 Aesthetic

The textile material may have a solid color aesthetic or a melangeaesthetic. A melange material may be considered a material that has beenmade with more than one color of fabric/textile/yarn, either by usingdifferent color fabrics/textiles/yarns or made with differentfabrics/textiles/yarns which are then individually dyed. A melangematerial may be desirable as it may have a greater ability to hide dirtor grime thereby more easily improving the sense of cleanliness of theproduct. A melange material may also provide benefits duringmanufacturing as it is easier to visually align the textile knitstructure correctly during cutting and/or overmolding.

However, a solid color material may be desirable as it provides greateroptions for finer gauge materials (e.g., 55 GG+) which are softer andtherefore more comfortable to the patient.

5.3.5.3 Illustrated Examples of Support Structure and Sealing PortionArrangements

FIGS. 81-112 show a number of different cushion assembly configurationsincluding various support structure and sealing portion arrangementsand/or processes. It is noted that these examples can be applied to anyof the patient interfaces and/or cushion assemblies described in thedisclosure. Further, any feature of any example may be applied to adifferent example and/or used with different features. The plenumchambers, support structures and sealing portions shown in these figuresmay be constructed from any of the suitable materials described earlier.It should also be noted that components, for example the supportstructure, may comprise more than one material. For example, anunderlying cushion of a support structure may comprise a differentmaterial than other portions of the support structure.

Referring to FIG. 83, support structure 10120 is removably connected toplenum chamber 10200 via clip 10126 on the support structure andconnector 10210 on the plenum chamber to form cavity 10001. In someexamples, the clip 10126 may be formed from polyurethane, polypropylene(PP) or polyethylene terephthalate (PET). Plenum chamber 10200 may beconstructed from a material that is more rigid than the clip, such aspolycarbonate or polyurethane having a higher Shore A hardness than theclip. The support structure 10120 and sealing portion 10130 areconfigured into a cushion arrangement having a single air assistedsealing portion 10130 (e.g., textile membrane).

The connection between the outer perimeter (or outer edge) of thetextile membrane and the inner edge of the support structure may beformed in a number of different ways. As shown in FIGS. 83 and 85, theconnection may form a lap joint where an edge portion of the textilemembrane overlaps with an edge portion of the support structure. In anexample, an attachment portion 10122 of the support structure may form arecessed portion to receive the sealing portion 10130 so that thesupport structure and sealing portion form a smooth outer surface, asshown in FIG. 83. The overlap may be minimal and provided only formanufacturing purposes (i.e., necessary in order to attach the sealingportion and the support structure) by for example, overmolding and/orinjection molding. This is in contrast to conventional arrangements inwhich the overlapping region may be arranged to provide additionalsupport (e.g., stiffness) to the sealing portion due to the presence ofthe support structure (in such arrangements, the overlap may vary aroundthe perimeter of the seal-forming structure to vary the level of supportor stiffness (e.g., less overlap, less support, more flexibitly, lesstension in sensitive nasal bridge region).

In contrast to the above described lap joint, the connection between thetextile membrane and the support structure may form an end-to-end joint(e.g., butt joint), as shown in FIG. 84. Due to manufacturing techniques(e.g., overmolding, injection molding), the end-to-end joint may havesome overlap, however such overlap is negligible and constant around theperimeter of the sealing portion at the connection with the supportstructure. In other words, as described above, any overlap of thesupport structure and the textile membrane is not designed to adjust thestiffness, tension, flexibility or support in different regions of theface (e.g., less overlap, less support, more flexible, less tension insensitive nasal bridge region).

Instead, whether a lap joint or end-to-end joint is provided, thepresent arrangement allows the compliant textile membrane toappropriately accommodate the patient's facial features. That is, theseal-forming structure is designed to allow the patient's facialfeatures (e.g., nose) to sink into the textile membrane whichcompliantly receives the patient's face.

The sealing portion may be glued, molded (e.g., overmolded or injectionmolded) or otherwise attached to the support structure. In analternative example, the recessed portion may be removed and theattachment portion 10122 may be used to attach the sealing portion 10130and the support structure 10120 end to end, as shown in FIG. 84.Further, FIG. 84 also illustrates that portions (d1) of the supportstructure 10120 adjacent to or connecting to the plenum chamber 10200may be thicker than portions (d2) of the support structure 10120adjacent to or connecting to the sealing portion 10130 so as to providestructural stability at the connection with the plenum chamber andflexibility at the interface with the patient.

In FIG. 85, the support structure 10120 includes an underlying cushion10121. The support structure also includes a sealing lip 10124 to sealthe interface between the plenum chamber 10200 and the support structure10120. The attachment portion 10122 of the support structure may beconfigured so as sandwich an end portion of the sealing portion betweenopposing sections of the attachment portion 10122.

In another example, plenum chamber 11200 may have an underlying cushion11121 attached to an inner portion thereof, as shown in FIG. 86. Assuch, the underlying cushion 11121 may be permanently attached to theplenum chamber 11200, whereas the support structure 10120 and sealingportion 10130 may be removably connected to the plenum chamber via clip10126 and connector 10210.

Referring to FIGS. 87 and 88, support structure 10120 may have anexternal seal biasing portion 10140 or an internal seal biasing portion10140′ which may utilize the internal air pressure in the cavity todynamically support the support structure and sealing portion 10130. Thesupport structure 10120 may include an inwardly curved end portion 10142thus forming an air-assisted support region 10144 which may optimize theforce, due to air pressure within the cavity, acting on the supportstructure and sealing portion to urge the sealing portion into sealingcontact with the patient's face.

Turning to FIG. 89, support structure 12120 includes an underlyingcushion 12121. The support structure and/or underlying cushion may beformed, for example, of molded polyurethane. In this example, thesealing portion 10130 is adhered to the support structure with anadhesive 10150 (e.g., heat-activated polyurethane, tape, glue).

In FIG. 90A, support structure 15120 is removably connected to plenumchamber 10200. The support structure includes an underlying cushion15121. In this example, the support structure is formed of foam (e.g.,polyurethane foam molding), but may also be formed of TPE, TPU or anyother suitable material. The sealing portion 10130 may have a membranelayer or film laminate layer 10131 to provide a substantially air-tightmaterial, as shown in FIG. 90A-1. Alternatively, the support structure15120 may be glued, bonded, or otherwise attached to the plenum chamber10200.

FIG. 90B shows an example similar to that of FIG. 90A, however thesealing portion 10130 in FIG. 90B is connected directly to the plenumchamber 10200 and may form a seamless cover over the underlying cushion15121. The sealing portion 10130 and underlying cushion 15121 may beglued or otherwise bonded to the plenum chamber 10200. Alternatively,the sealing portion 10130 and/or the underlying cushion 15121 may beremovably connected to the plenum chamber.

Referring to FIG. 91, support structure 17120 includes a first portion17123 and an underlying cushion 17121. The first portion 17123, whichmay connect to the plenum chamber, may be constructed from a materialthat is more rigid than a material of the underlying cushion 17121. Forexample, the first portion 17123 and the underlying cushion may both beconstructed of polyurethane, but the polyurethane material of the firstportion may have a higher hardness than the material of the underlyingcushion. A reinforcing member 17125 may extend along an outer perimeterof the cushion bridging the intersection between the first portion 17123and the underlying cushion 17121 to provide structural support.

As shown in FIG. 92, support structure 23120 may include an underlyingcushion 23121 (e.g., constructed of TPU) having a U-shape or hook shape.The underlying cushion may include a clip 23126 for removable connectionto the cushion (e.g., the frame, plenum chamber, or other portion of thesupport structure). Alternatively, the sealing portion 10130 may beattached to the support structure 23120 as a removable module that as aunit may be removably connected to the cushion (e.g., the frame, plenumchamber, or other portion of the support structure). The sealing portion10130 may be attached to the underlying cushion 23121, for example, bythermoforming. The underlying cushion also may be shaped bythermoforming.

Support structure 24120 may include a rigid clip 24126 that supports anunderlying cushion 24121, as shown in FIG. 93. The underlying cushion24121 may include an outer textile layer 10132 and an inner layer (e.g.,constructed of foam) enclosed by the textile layer and the clip. Thesupport structure 24120 may be removably connectable to the cushion(e.g., the frame, plenum chamber, or other portion of the supportstructure). Alternatively, the sealing portion 10130 may be attached tothe support structure 24120 as a removable module that as a unit may beremovably connected to the cushion (e.g., the frame, plenum chamber, orother portion of the support structure). The sealing portion 10130 maybe attached to the underlying cushion 24121, for example, bythermoforming. The underlying cushion also may be shaped bythermoforming.

Referring to FIG. 94, support structure 18120 may include a rigid clip18126 that supports an underlying cushion 18121 (e.g., constructed offoam). The support structure 18120 may be removably connectable to thecushion (e.g., the frame, plenum chamber, or other portion of thesupport structure). Alternatively, the sealing portion 10130 may beattached to the support structure 18120 as a removable module that as aunit may be removably connected to the cushion (e.g., the frame, plenumchamber, or other portion of the support structure). The sealing portion10130 may be attached to the underlying cushion 18121, for example, bythermoforming. The underlying cushion also may be shaped bythermoforming.

Turning to FIG. 95, support structure 19120 includes a first portion19123 and an underlying cushion 19121. The first portion 19123, whichmay connect to the plenum chamber, may be constructed of a material thatis more rigid than a material of the underlying cushion 19121. Forexample, the first portion may be constructed from polyurethane and theunderlying cushion may be constructed from foam.

Referring to FIG. 96, support structure 20120 includes a first portion20123 and an underlying cushion 20121. The first portion 20123, whichmay connect to the plenum chamber, may be constructed from a materialthat has different rigidity or Shore A hardness than a material of theunderlying cushion. For example, the first portion 20123 and theunderlying cushion 20121 may both be constructed of polyurethane,whereas the first portion 20123 may be less or more rigid or have higheror lower Shore A hardness than the underlying cushion 20121. In analternative example, the first portion 20123 and the underlying cushion20121 may be constructed of the same material and may have the samerigidity or Shore A hardness.

The support structure 21120 of FIG. 97 includes a first portion 21123and an underlying cushion 21121 and is similar to support structure20120 discussed above, except that the cushion includes a second sealingportion layer (e.g., textile layer 10132) forming dual textilemembranes. The underlying cushion 21121 may be molded or otherwiseattached to an underside of the textile layer 10132.

Referring to FIG. 98, support structure 22120 includes a first portion22123 and an underlying cushion 22121 and is similar to supportstructure 21120 discussed above, except that the underlying cushion22121 is a foam layer laminated or otherwise attached to the undersideof the textile layer 10132.

Turning to FIG. 99, the illustrated cushion assembly includes a dualsealing portion structure without underlying cushion support. Thecushion assembly includes a first textile layer 10130 and second textilelayer 10132 connected to support structure 10120.

The cushion assembly in FIG. 100 is similar to the cushion assembly inFIG. 99, except that the sealing portion includes a support section10135 from which the first textile layer 10130 and the second textilelayer 10132 extend. Support section 10135 may be constructed of TPU orfoam (e.g., polyurethane foam molding), for example. The support section10135 may add resilience to the sealing portion and allow the textilelayers to spring back more quickly from external forces. The supportsection 10135 may be removably connected, as a modular unit with thetextile layers, to support structure 10120. In an alternative example,the support section 10135 is removably connected to the plenum chamber.

Turning to FIGS. 101 and 102, sealing portion modular assembly 26400 maybe permanently or removably connected (e.g., with a mechanical clip) tosupport structure 26120 (or alternatively to plenum chamber 10200). Thesealing portion modular assembly may include a skeleton supporting frame26450 having the sealing portion 10130 attached thereto. The sealingportion 10130 may be thermoformed or insert molded, for example, toattach the sealing portion to the supporting frame 26450. Thethermoforming or molding process and/or the supporting frame itself mayform and hold the sealing portion in a curved or three-dimensionalshape. Support structure 26120 may be constructed from insert moldedpolyurethane, for example.

In the example of FIG. 103, the textile membrane 10130 and/or supportstructure may be configured to be removable or modular. As illustratedin FIG. 103, the textile membrane 10130 may be attached to a modularsupport structure 26480 around its perimeter. The modular supportstructure 26480 may then be removably engaged as a module to the plenumchamber. A modular form may advantageously reduce the occurrence ofprotruding folds or wrinkles in the textile membrane surface.

In some forms, the textile membrane may be a sleeve or sock that isadapted to cover and be retained above the plenum chamber or supportstructure.

A modular textile membrane seal may also substantially simplify themanufacturing as all the complex bonding may be done in a simpleunstressed state. While some textiles may be treated to havesubstantially self-cleaning properties, the use of a modular textilemembrane may also advantageously provide a cheaper and more hygienicalternative. In some forms, the textile membrane or support structurecan be a removable and/or replaceable sub-assembly that attaches to theplenum chamber, support structure or frame assembly.

In forms where the textile membrane is attached to a supporting frame ofthe modular supporting structure 26480, the supporting frame can bepre-formed to be either flat (as shown in FIG. 103) or as a 3-Dstructure such as an arc.

In some forms, the modular supporting structure 26480 can engage theplenum chamber through corresponding male/female location pins/holes. Insome forms, the modular supporting structure may utilize a tongue andgroove arrangement around the peripheral sides of the structure to forman effective air-tight seal with the plenum chamber. The modularsupporting structure 26480 may be formed, for example, from a plasticmaterial, polyurethane, or similar materials.

Turning to FIGS. 104-106, a process of insert molding the sealingportion (e.g., a textile material) as an In Mold Decoration (IMD) isillustrated. As shown in FIGS. 104 and 105, a first mold 26500 may bebrought into contact with a second mold 26550 to attach the sealingportion 10130 to the supporting frame 26450 while also impartingcurvature to the sealing portion. The molding process may also stretchthe sealing portion 10130 so that attachment of the sealing portion tothe supporting frame 26450 maintains the sealing portion in tensionprior to use.

Referring to FIGS. 107 and 108, a one size fits all cushion assembly27105 is shown. Cushion assembly 27105 may include a sealing portion10130 attached to an upper supporting frame portion 27202 and a lowersupporting frame portion 27204. The upper supporting frame portion 27202may be spaced from the lower supporting frame portion 27204 therebyforming an elastic region 27108 in which the sealing portion may stretchto distance the upper supporting frame portion 27202 and the lowersupporting frame portion 27204 to accommodate a range of patient facesizes.

A patient's face may be scanned to create a custom mask, as shown inFIGS. 109 and 110. A three-dimensional profile may be obtained by facialscan to create a cushion assembly 28105 including a sealing portion10130 attached to a supporting frame 28200. Supporting frame 28200 mayinclude a relatively rigid support element (e.g., a polyurethane moldedpiece) and a cushioning element (e.g., foam) between the support elementand the sealing portion. As shown in FIG. 84, the cushion assembly maybe arranged to stretch to accommodate different patient face sizes.

In some examples of the nasal cushion, such as shown for example inFIGS. 111 and 112, the support structure 3120 may actually be configuredto deform inwardly at certain fold or pivot points. For example, thinnerregions of the support structure may be designed to created fold orpivot points. In an example, a bottom central portion (e.g., nose baseregion 3112) of the support structure 3120 may have a relatively reducedthickness such that when stress is applied to the walls of the supportstructure due to engagement by the patient's face, the bottom centralportion of the support structure may create a pivot point thus allowingthe left and right lateral sides of the support structure to deforminwardly to cradle the patient's face (e.g., nose) thereby accommodatingengagement of the patient'. An upper anterior region 3109 may also havea reduced thickness as compared to lateral support regions 3122 so as tocreate a fold or pivot point.

Thus, in the example of FIGS. 111 and 112, the support structure 3120may have three regions of different stiffness (e.g., by having differentthicknesses). The upper anterior region 3109 may have a thickness thatis the same as or greater than the thickness of the nose base region3112. The lateral support regions 3122 may have a thickness that isgreater than the thickness of the upper anterior region 3109 and thenose base region 3112. Thus, the lateral support region may be stifferthan the upper anterior region 3109 which may be stiffer than the nosebase region 3112. It is noted that the plenum chamber and the supportstructure may both be formed of a flexible material (e.g., silicone) andmay form a one-piece structure (e.g., molded together). This may assistthe bending/folding/pivoting of the cushion assembly to accommodate thepatient's facial features. In an example, the seal-forming structure maybe an extension of the plenum chamber or formed as a part of the plenumchamber such that the plenum chamber encompasses the seal-formingstructure. In such an example, the support structure and textilemembrane may be considered part of the plenum chamber.

5.4 RPT Device

An RPT device 4000 in accordance with one aspect of the presenttechnology comprises mechanical, pneumatic, and/or electrical componentsand is configured to execute one or more algorithms 4300, such as any ofthe methods, in whole or in part, described herein. The RPT device 4000may be configured to generate a flow of air for delivery to a patient'sairways, such as to treat one or more of the respiratory conditionsdescribed elsewhere in the present document.

In one form, the RPT device 4000 is constructed and arranged to becapable of delivering a flow of air in a range of −20 L/min to +150L/min while maintaining a positive pressure of at least 6 cmH₂O, or atleast 10cmH₂O, or at least 20 cmH₂O.

The RPT device may have an external housing 4010, formed in two parts,an upper portion 4012 and a lower portion 4014. Furthermore, theexternal housing 4010 may include one or more panel(s) 4015. The RPTdevice 4000 comprises a chassis 4016 that supports one or more internalcomponents of the RPT device 4000. The RPT device 4000 may include ahandle 4018.

The pneumatic path of the RPT device 4000 may comprise one or more airpath items, e.g., an inlet air filter 4112, an inlet muffler 4122, apressure generator capable of supplying air at positive pressure (e.g.,a blower 4142), an outlet muffler 4124 and one or more transducers 4270,such as pressure sensors 4272 and flow rate sensors 4274.

One or more of the air path items may be located within a removableunitary structure which will be referred to as a pneumatic block 4020.The pneumatic block 4020 may be located within the external housing4010. In one form a pneumatic block 4020 is supported by, or formed aspart of the chassis 4016.

The RPT device 4000 may have an electrical power supply 4210, one ormore input devices 4220, a central controller, a therapy devicecontroller, a pressure generator, one or more protection circuits,memory, transducers, data communication interface and one or more outputdevices. Electrical components 4200 may be mounted on a single PrintedCircuit Board Assembly (PCBA) 4202. In an alternative form, the RPTdevice 4000 may include more than one PCBA 4202.

5.5 Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

5.5.1 General

Air: In certain forms of the present technology, air may be taken tomean atmospheric air, and in other forms of the present technology airmay be taken to mean some other combination of breathable gases, e.g.atmospheric air enriched with oxygen.

Ambient: In certain forms of the present technology, the term ambientwill be taken to mean (i) external of the treatment system or patient,and (ii) immediately surrounding the treatment system or patient.

For example, ambient humidity with respect to a humidifier may be thehumidity of air immediately surrounding the humidifier, e.g. thehumidity in the room where a patient is sleeping. Such ambient humiditymay be different to the humidity outside the room where a patient issleeping.

In another example, ambient pressure may be the pressure immediatelysurrounding or external to the body.

In certain forms, ambient (e.g., acoustic) noise may be considered to bethe background noise level in the room where a patient is located, otherthan for example, noise generated by an RPT device or emanating from amask or patient interface. Ambient noise may be generated by sourcesoutside the room.

Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in whichthe treatment pressure is automatically adjustable, e.g. from breath tobreath, between minimum and maximum limits, depending on the presence orabsence of indications of SDB events.

Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressuretherapy in which the treatment pressure is approximately constantthrough a respiratory cycle of a patient. In some forms, the pressure atthe entrance to the airways will be slightly higher during exhalation,and slightly lower during inhalation. In some forms, the pressure willvary between different respiratory cycles of the patient, for example,being increased in response to detection of indications of partial upperairway obstruction, and decreased in the absence of indications ofpartial upper airway obstruction.

Flow rate: The volume (or mass) of air delivered per unit time. Flowrate may refer to an instantaneous quantity. In some cases, a referenceto flow rate will be a reference to a scalar quantity, namely a quantityhaving magnitude only. In other cases, a reference to flow rate will bea reference to a vector quantity, namely a quantity having bothmagnitude and direction. Flow rate may be given the symbol Q. ‘Flowrate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

In the example of patient respiration, a flow rate may be nominallypositive for the inspiratory portion of a breathing cycle of a patient,and hence negative for the expiratory portion of the breathing cycle ofa patient. Total flow rate, Qt, is the flow rate of air leaving the RPTdevice. Vent flow rate, Qv, is the flow rate of air leaving a vent toallow washout of exhaled gases. Leak flow rate, Ql, is the flow rate ofleak from a patient interface system or elsewhere. Respiratory flowrate, Qr, is the flow rate of air that is received into the patient'srespiratory system.

Humidifier: The word humidifier will be taken to mean a humidifyingapparatus constructed and arranged, or configured with a physicalstructure to be capable of providing a therapeutically beneficial amountof water (H₂O) vapour to a flow of air to ameliorate a medicalrespiratory condition of a patient.

Leak: The word leak will be taken to be an unintended flow of air. Inone example, leak may occur as the result of an incomplete seal betweena mask and a patient's face. In another example leak may occur in aswivel elbow to the ambient.

Noise, conducted (acoustic): Conducted noise in the present documentrefers to noise which is carried to the patient by the pneumatic path,such as the air circuit and the patient interface as well as the airtherein. In one form, conducted noise may be quantified by measuringsound pressure levels at the end of an air circuit.

Noise, radiated (acoustic): Radiated noise in the present documentrefers to noise which is carried to the patient by the ambient air. Inone form, radiated noise may be quantified by measuring soundpower/pressure levels of the object in question according to ISO 3744.

Noise, vent (acoustic): Vent noise in the present document refers tonoise which is generated by the flow of air through any vents such asvent holes of the patient interface.

Patient: A person, whether or not they are suffering from a respiratorycondition.

Pressure: Force per unit area. Pressure may be expressed in a range ofunits, including cmH₂O, g-f/cm² and hectopascal. 1 cmH₂O is equal to 1g-f/cm² and is approximately 0.98 hectopascal. In this specification,unless otherwise stated, pressure is given in units of cmH₂O.

The pressure in the patient interface is given the symbol Pm, while thetreatment pressure, which represents a target value to be achieved bythe mask pressure Pm at the current instant of time, is given the symbolPt.

Respiratory Pressure Therapy (RPT): The application of a supply of airto an entrance to the airways at a treatment pressure that is typicallypositive with respect to atmosphere.

Ventilator: A mechanical device that provides pressure support to apatient to perform some or all of the work of breathing.

5.5.1.1 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression moulded silicone rubber (CMSR). One formof commercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, an exemplary form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240.

Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.

5.5.1.2 Mechanical Properties

Resilience: Ability of a material to absorb energy when deformedelastically and to release the energy upon unloading.

Resilient: Will release substantially all of the energy when unloaded.Includes e.g. certain silicones, and thermoplastic elastomers.

Hardness: The ability of a material per se to resist deformation (e.g.described by a Young's Modulus, or an indentation hardness scalemeasured on a standardised sample size).

-   -   ‘Soft’ materials may include silicone or 145hermos-plastic        elastomer (TPE), and may, e.g. readily deform under finger        pressure.    -   ‘Hard’ materials may include polycarbonate, polypropylene, steel        or aluminium, and may not e.g. readily deform under finger        pressure.

Stiffness (or rigidity) of a structure or component: The ability of thestructure or component to resist deformation in response to an appliedload. The load may be a force or a moment, e.g. compression, tension,bending or torsion. The structure or component may offer differentresistances in different directions.

Floppy structure or component: A structure or component that will changeshape, e.g. bend, when caused to support its own weight, within arelatively short period of time such as 1 second.

Rigid structure or component: A structure or component that will notsubstantially change shape when subject to the loads typicallyencountered in use. An example of such a use may be setting up andmaintaining a patient interface in sealing relationship with an entranceto a patient's airways, e.g. at a load of approximately 20 to 30 cmH₂Opressure.

As an example, an I-beam may comprise a different bending stiffness(resistance to a bending load) in a first direction in comparison to asecond, orthogonal direction. In another example, a structure orcomponent may be floppy in a first direction and rigid in a seconddirection.

5.5.2 Respiratory Cycle

Apnea: According to some definitions, an apnea is said to have occurredwhen flow falls below a predetermined threshold for a duration, e.g. 10seconds. An obstructive apnea will be said to have occurred when,despite patient effort, some obstruction of the airway does not allowair to flow. A central apnea will be said to have occurred when an apneais detected that is due to a reduction in breathing effort, or theabsence of breathing effort, despite the airway being patent. A mixedapnea occurs when a reduction or absence of breathing effort coincideswith an obstructed airway.

Breathing rate: The rate of spontaneous respiration of a patient,usually measured in breaths per minute.

Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

Effort (breathing): The work done by a spontaneously breathing personattempting to breathe.

Expiratory portion of a breathing cycle: The period from the start ofexpiratory flow to the start of inspiratory flow.

Flow limitation: Flow limitation will be taken to be the state ofaffairs in a patient's respiration where an increase in effort by thepatient does not give rise to a corresponding increase in flow. Whereflow limitation occurs during an inspiratory portion of the breathingcycle it may be described as inspiratory flow limitation. Where flowlimitation occurs during an expiratory portion of the breathing cycle itmay be described as expiratory flow limitation.

Types of flow limited inspiratory waveforms:

-   -   (ii) Flattened: Having a rise followed by a relatively flat        portion, followed by a fall.    -   (ii) M-shaped: Having two local peaks, one at the leading edge,        and one at the trailing edge, and a relatively flat portion        between the two peaks.    -   (ii) Chair-shaped: Having a single local peak, the peak being at        the leading edge, followed by a relatively flat portion.    -   (ii) Reverse-chair shaped: Having a relatively flat portion        followed by single local peak, the peak being at the trailing        edge.

Hypopnea: According to some definitions, a hypopnea is taken to be areduction in flow, but not a cessation of flow. In one form, a hypopneamay be said to have occurred when there is a reduction in flow below athreshold rate for a duration. A central hypopnea will be said to haveoccurred when a hypopnea is detected that is due to a reduction inbreathing effort. In one form in adults, either of the following may beregarded as being hypopneas:

-   -   (ii) a 30% reduction in patient breathing for at least 10        seconds plus an associated 4% desaturation; or    -   (ii) a reduction in patient breathing (but less than 50%) for at        least 10 seconds, with an associated desaturation of at least 3%        or an arousal.

Hyperpnea: An increase in flow to a level higher than normal.

Inspiratory portion of a breathing cycle: The period from the start ofinspiratory flow to the start of expiratory flow will be taken to be theinspiratory portion of a breathing cycle.

Patency (airway): The degree of the airway being open, or the extent towhich the airway is open. A patent airway is open. Airway patency may bequantified, for example with a value of one (1) being patent, and avalue of zero (0), being closed (obstructed).

Positive End-Expiratory Pressure (PEEP): The pressure above atmospherein the lungs that exists at the end of expiration.

Peak flow rate (Qpeak): The maximum value of flow rate during theinspiratory portion of the respiratory flow waveform.

Respiratory flow rate, patient airflow rate, respiratory airflow rate(Qr): These terms may be understood to refer to the RPT device'sestimate of respiratory flow rate, as opposed to “true respiratory flowrate” or “true respiratory flow rate”, which is the actual respiratoryflow rate experienced by the patient, usually expressed in litres perminute.

Tidal volume (Vt): The volume of air inhaled or exhaled during normalbreathing, when extra effort is not applied. In principle theinspiratory volume Vi (the volume of air inhaled) is equal to theexpiratory volume Ve (the volume of air exhaled), and therefore a singletidal volume Vt may be defined as equal to either quantity. In practicethe tidal volume Vt is estimated as some combination, e.g. the mean, ofthe inspiratory volume Vi and the expiratory volume Ve.

(inhalation) Time (Ti): The duration of the inspiratory portion of therespiratory flow rate waveform.

(exhalation) Time (Te): The duration of the expiratory portion of therespiratory flow rate waveform.

(total) Time (Ttot): The total duration between the start of oneinspiratory portion of a respiratory flow rate waveform and the start ofthe following inspiratory portion of the respiratory flow rate waveform.

Typical recent ventilation: The value of ventilation around which recentvalues of ventilation Vent over some predetermined timescale tend tocluster, that is, a measure of the central tendency of the recent valuesof ventilation.

Upper airway obstruction (UAO): includes both partial and total upperairway obstruction. This may be associated with a state of flowlimitation, in which the flow rate increases only slightly or may evendecrease as the pressure difference across the upper airway increases(Starling resistor behaviour).

Ventilation (Vent): A measure of a rate of gas being exchanged by thepatient's respiratory system. Measures of ventilation may include one orboth of inspiratory and expiratory flow, per unit time. When expressedas a volume per minute, this quantity is often referred to as “minuteventilation”. Minute ventilation is sometimes given simply as a volume,understood to be the volume per minute.

5.5.3 Ventilation

Adaptive Servo-Ventilator (ASV): A servo-ventilator that has achangeable, rather than fixed target ventilation. The changeable targetventilation may be learned from some characteristic of the patient, forexample, a respiratory characteristic of the patient.

Backup rate: A parameter of a ventilator that establishes the minimumbreathing rate (typically in number of breaths per minute) that theventilator will deliver to the patient, if not triggered by spontaneousrespiratory effort.

Cycled: The termination of a ventilator's inspiratory phase. When aventilator delivers a breath to a spontaneously breathing patient, atthe end of the inspiratory portion of the breathing cycle, theventilator is said to be cycled to stop delivering the breath.

Expiratory positive airway pressure (EPAP): a base pressure, to which apressure varying within the breath is added to produce the desired maskpressure which the ventilator will attempt to achieve at a given time.

End expiratory pressure (EEP): Desired mask pressure which theventilator will attempt to achieve at the end of the expiratory portionof the breath. If the pressure waveform template Π(Φ) is zero-valued atthe end of expiration, i.e. Π(Φ)=0 when Φ=1, the EEP is equal to theEPAP.

Inspiratory positive airway pressure (IPAP): Maximum desired maskpressure which the ventilator will attempt to achieve during theinspiratory portion of the breath.

Pressure support: A number that is indicative of the increase inpressure during ventilator inspiration over that during ventilatorexpiration, and generally means the difference in pressure between themaximum value during inspiration and the base pressure (e.g.,PS=IPAP−EPAP). In some contexts pressure support means the differencewhich the ventilator aims to achieve, rather than what it actuallyachieves.

Servo-ventilator: A ventilator that measures patient ventilation, has atarget ventilation, and which adjusts the level of pressure support tobring the patient ventilation towards the target ventilation.

Spontaneous/Timed (S/T): A mode of a ventilator or other device thatattempts to detect the initiation of a breath of a spontaneouslybreathing patient. If however, the device is unable to detect a breathwithin a predetermined period of time, the device will automaticallyinitiate delivery of the breath.

Swing: Equivalent term to pressure support.

Triggered: When a ventilator delivers a breath of air to a spontaneouslybreathing patient, it is said to be triggered to do so at the initiationof the respiratory portion of the breathing cycle by the patient'sefforts.

5.5.4 Anatomy 5.5.4.1 Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alar angle:

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricle: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankforthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the greater alarcartilage.

Lip, lower (labrale inferius):

Lip, upper (labrale superius):

Greater alar cartilage: A plate of cartilage lying below the lateralnasal cartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear). The midsagittal plane is a sagittal plane that dividesthe body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramenton: The point of greatest concavity in the midline of the lowerlip between labrale inferius and soft tissue pogonion

5.5.4.2 Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama occipitalis.

Orbit: The bony cavity in the skull to contain the eyeball.

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

5.5.4.3 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx) (the nasal part of the pharynx), the oropharynx(mesopharynx) (the oral part of the pharynx), and the laryngopharynx(hypopharynx).

5.5.5 Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: An elbow is an example of a structure that directs an axis offlow of air travelling therethrough to change direction through anangle. In one form, the angle may be approximately 90 degrees. Inanother form, the angle may be more, or less than 90 degrees. The elbowmay have an approximately circular cross-section. In another form theelbow may have an oval or a rectangular cross-section. In certain formsan elbow may be rotatable with respect to a mating component, e.g. about360 degrees. In certain forms an elbow may be removable from a matingcomponent, e.g. via a snap connection. In certain forms, an elbow may beassembled to a mating component via a one-time snap during manufacture,but not removable by a patient.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Functional Dead Space:

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. For example theheadgear may comprise a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a thin structural element thathas:

-   -   resistance to being stretched; and    -   substantially no resistance to bending.

A membrane may be curved.

Plenum chamber: a mask plenum chamber will be taken to mean a portion ofa patient interface having walls at least partially enclosing a volumeof space, the volume having air therein pressurised above atmosphericpressure in use. A shell may form part of the walls of a mask plenumchamber.

Seal: May be a noun form (“a seal”) which refers to a structure, or averb form (“to seal”) which refers to the effect. Two elements may beconstructed and/or arranged to ‘seal’ or to effect ‘sealing’therebetween without requiring a separate ‘seal’ element per se.

Shell: A shell will be taken to mean a curved, relatively thinstructural element having bending, tensile and compressive stiffness.For example, a curved structural wall of a mask may be a shell. In someforms, a shell may be faceted. In some forms a shell may be airtight. Insome forms a shell may not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel (noun): A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. There may be little orno leak flow of air from the swivel in use.

Tie (noun): A structure designed to resist tension.

Vent: (noun): A structure that allows a flow of air from an interior ofthe mask, or conduit, to ambient air for clinically effective washout ofexhaled gases. For example, a clinically effective washout may involve aflow rate of about 10 litres per minute to about 100 litres per minute,depending on the mask design and treatment pressure.

5.5.6 Shape of Structures

Products in accordance with the present technology may comprise one ormore three-dimensional mechanical structures, for example a mask cushionor an impeller. The three-dimensional structures may be bounded bytwo-dimensional surfaces. These surfaces may be distinguished using alabel to describe an associated surface orientation, location, function,or some other characteristic. For example a structure may comprise oneor more of an anterior surface, a posterior surface, an interior surfaceand an exterior surface. In another example, a seal-forming structuremay comprise a face-contacting (e.g. outer) surface, and a separatenon-face-contacting (e.g. underside or inner) surface. In anotherexample, a structure may comprise a first surface and a second surface.

To facilitate describing the shape of the three-dimensional structuresand the surfaces, we first consider a cross-section through a surface ofthe structure at a point, p. See FIG. 3B to FIG. 3F, which illustrateexamples of cross-sections at point p on a surface, and the resultingplane curves. FIGS. 3B to 3F also illustrate an outward normal vector atp. The outward normal vector at p points away from the surface. In someexamples we describe the surface from the point of view of an imaginarysmall person standing upright on the surface.

5.5.6.1 Curvature in One Dimension

The curvature of a plane curve at p may be described as having a sign(e.g. positive, negative) and a magnitude (e.g. 1/radius of a circlethat just touches the curve at p).

Positive curvature: If the curve at p turns towards the outward normal,the curvature at that point will be taken to be positive (if theimaginary small person leaves the point p they must walk uphill). SeeFIG. 3B (relatively large positive curvature compared to FIG. 3C) andFIG. 3C (relatively small positive curvature compared to FIG. 3B). Suchcurves are often referred to as concave.

Zero curvature: If the curve at p is a straight line, the curvature willbe taken to be zero (if the imaginary small person leaves the point p,they can walk on a level, neither up nor down). See FIG. 3D.

Negative curvature: If the curve at p turns away from the outwardnormal, the curvature in that direction at that point will be taken tobe negative (if the imaginary small person leaves the point p they mustwalk downhill). See FIG. 3E (relatively small negative curvaturecompared to FIG. 3F) and FIG. 3F (relatively large negative curvaturecompared to FIG. 3E). Such curves are often referred to as convex.

5.5.6.2 Curvature of Two Dimensional Surfaces

A description of the shape at a given point on a two-dimensional surfacein accordance with the present technology may include multiple normalcross-sections. The multiple cross-sections may cut the surface in aplane that includes the outward normal (a “normal plane”), and eachcross-section may be taken in a different direction. Each cross-sectionresults in a plane curve with a corresponding curvature. The differentcurvatures at that point may have the same sign, or a different sign.Each of the curvatures at that point has a magnitude, e.g. relativelysmall. The plane curves in FIGS. 3B to 3F could be examples of suchmultiple cross-sections at a particular point.

Principal curvatures and directions: The directions of the normal planeswhere the curvature of the curve takes its maximum and minimum valuesare called the principal directions. In the examples of FIG. 3B to FIG.3F, the maximum curvature occurs in FIG. 3B, and the minimum occurs inFIG. 3F, hence FIG. 3B and FIG. 3F are cross sections in the principaldirections. The principal curvatures at p are the curvatures in theprincipal directions.

Region of a surface: A connected set of points on a surface. The set ofpoints in a region may have similar characteristics, e.g. curvatures orsigns.

Saddle region: A region where at each point, the principal curvatureshave opposite signs, that is, one is positive, and the other is negative(depending on the direction to which the imaginary person turns, theymay walk uphill or downhill).

Dome region: A region where at each point the principal curvatures havethe same sign, e.g. both positive (a “concave dome”) or both negative (a“convex dome”).

Cylindrical region: A region where one principal curvature is zero (or,for example, zero within manufacturing tolerances) and the otherprincipal curvature is non-zero.

Planar region: A region of a surface where both of the principalcurvatures are zero (or, for example, zero within manufacturingtolerances).

Edge of a surface: A boundary or limit of a surface or region.

Path: In certain forms of the present technology, ‘path’ will be takento mean a path in the mathematical-topological sense, e.g. a continuousspace curve from f(0) to f(1) on a surface. In certain forms of thepresent technology, a ‘path’ may be described as a route or course,including e.g. a set of points on a surface. (The path for the imaginaryperson is where they walk on the surface, and is analogous to a gardenpath).

Path length: In certain forms of the present technology, ‘path length’will be taken to mean the distance along the surface from f(0) to f(1),that is, the distance along the path on the surface. There may be morethan one path between two points on a surface and such paths may havedifferent path lengths. (The path length for the imaginary person wouldbe the distance they have to walk on the surface along the path).

Straight-line distance: The straight-line distance is the distancebetween two points on a surface, but without regard to the surface. Onplanar regions, there would be a path on the surface having the samepath length as the straight-line distance between two points on thesurface. On non-planar surfaces, there may be no paths having the samepath length as the straight-line distance between two points. (For theimaginary person, the straight-line distance would correspond to thedistance ‘as the crow flies’.)

5.5.6.3 Space Curves

Space curves: Unlike a plane curve, a space curve does not necessarilylie in any particular plane. A space curve may be closed, that is,having no endpoints. A space curve may be considered to be aone-dimensional piece of three-dimensional space. An imaginary personwalking on a strand of the DNA helix walks along a space curve. Atypical human left ear comprises a helix, which is a left-hand helix,see FIG. 3Q. A typical human right ear comprises a helix, which is aright-hand helix, see FIG. 3R. FIG. 3S shows a right-hand helix. Theedge of a structure, e.g. the edge of a membrane or impeller, may followa space curve. In general, a space curve may be described by a curvatureand a torsion at each point on the space curve. Torsion is a measure ofhow the curve turns out of a plane. Torsion has a sign and a magnitude.The torsion at a point on a space curve may be characterised withreference to the tangent, normal and binormal vectors at that point.

Tangent unit vector (or unit tangent vector): For each point on a curve,a vector at the point specifies a direction from that point, as well asa magnitude. A tangent unit vector is a unit vector pointing in the samedirection as the curve at that point. If an imaginary person were flyingalong the curve and fell off her vehicle at a particular point, thedirection of the tangent vector is the direction she would betravelling.

Unit normal vector: As the imaginary person moves along the curve, thistangent vector itself changes. The unit vector pointing in the samedirection that the tangent vector is changing is called the unitprincipal normal vector. It is perpendicular to the tangent vector.

Binormal unit vector: The binormal unit vector is perpendicular to boththe tangent vector and the principal normal vector. Its direction may bedetermined by a right-hand rule (see e.g. FIG. 3P), or alternatively bya left-hand rule (FIG. 3O).

Osculating plane: The plane containing the unit tangent vector and theunit principal normal vector. See FIGS. 30 and 3P.

Torsion of a space curve: The torsion at a point of a space curve is themagnitude of the rate of change of the binormal unit vector at thatpoint. It measures how much the curve deviates from the osculatingplane. A space curve which lies in a plane has zero torsion. A spacecurve which deviates a relatively small amount from the osculating planewill have a relatively small magnitude of torsion (e.g. a gently slopinghelical path). A space curve which deviates a relatively large amountfrom the osculating plane will have a relatively large magnitude oftorsion (e.g. a steeply sloping helical path). With reference to FIG.3S, since T2>T1, the magnitude of the torsion near the top coils of thehelix of FIG. 3S is greater than the magnitude of the torsion of thebottom coils of the helix of FIG. 3S

With reference to the right-hand rule of FIG. 3P, a space curve turningtowards the direction of the right-hand binormal may be considered ashaving a right-hand positive torsion (e.g. a right-hand helix as shownin FIG. 3S). A space curve turning away from the direction of theright-hand binormal may be considered as having a right-hand negativetorsion (e.g. a left-hand helix).

Equivalently, and with reference to a left-hand rule (see FIG. 3O), aspace curve turning towards the direction of the left-hand binormal maybe considered as having a left-hand positive torsion (e.g. a left-handhelix). Hence left-hand positive is equivalent to right-hand negative.See FIG. 3T.

5.5.6.4 Holes

A surface may have a one-dimensional hole, e.g. a hole bounded by aplane curve or by a space curve. Thin structures (e.g. a membrane) witha hole, may be described as having a one-dimensional hole. See forexample the one dimensional hole in the surface of structure shown inFIG. 3I, bounded by a plane curve.

A structure may have a two-dimensional hole, e.g. a hole bounded by asurface. For example, an inflatable tyre has a two dimensional holebounded by the interior surface of the tyre. In another example, abladder with a cavity for air or gel could have a two-dimensional hole.See for example the cushion of FIG. 3L and the example cross-sectionstherethrough in FIG. 3M and FIG. 3N, with the interior surface boundinga two dimensional hole indicated. In a yet another example, a conduitmay comprise a one-dimension hole (e.g. at its entrance or at its exit),and a two-dimension hole bounded by the inside surface of the conduit.See also the two dimensional hole through the structure shown in FIG.3K, bounded by a surface as shown.

5.6 Other Remarks

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in Patent Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being used to construct acomponent, obvious alternative materials with similar properties may beused as a substitute. Furthermore, unless specified to the contrary, anyand all components herein described are understood to be capable ofbeing manufactured and, as such, may be manufactured together orseparately.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated herein by referencein their entirety to disclose and describe the methods and/or materialswhich are the subject of those publications. The publications discussedherein are provided solely for their disclosure prior to the filing dateof the present application. Nothing herein is to be construed as anadmission that the present technology is not entitled to antedate suchpublication by virtue of prior invention. Further, the dates ofpublication provided may be different from the actual publication dates,which may need to be independently confirmed.

The terms “comprises” and “comprising” should be interpreted asreferring to elements, components, or steps in a non-exclusive manner,indicating that the referenced elements, components, or steps may bepresent, or utilized, or combined with other elements, components, orsteps that are not expressly referenced.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

5.7 Reference Signs List

-   Step 10-   Step 12-   Step 14-   Curve 35-   Transition portion 36-   Wale 70-   Course 80-   Warp knit 90-   Weft knit 100-   Patient 1000-   Bed partner 1100-   Patient interface 3000-   Seal-forming structure 3100-   Cavity 3101-   Naris opening 3102-   Bridge portion-   Cushion assembly 3105-   Frame connection opening 3106-   Upper anterior region 3109-   Nose base region 3112-   Support structure 3120-   Lateral support region 3122-   Sealing portion 3130-   Plenum chamber 3200-   Plenum chamber lateral end 3202-   Plenum chamber connector 3204-   Notch 3206-   Chamfered edge 3208-   Slot 3209-   Chord 3210-   Superior point 3220-   Inferior point 3230-   Lateral sides 3250-   Corner region 3252-   Medial subnasale region 3260-   Medical pronasale region 3270-   Positioning and stabilising structure 3300-   Lateral portion 3302-   Superior portion 3304-   Hub 3306-   Tab 3308-   Posterior strap 3310-   Posterior strap end portion 3311-   Sleeve 3312-   End 3314-   Vent 3400-   Decoupling structure vent 3402-   Decoupling structure 3500-   Swivel connector 3502-   Button 3504-   Connection port 3600-   Forehead support 3700-   RPT device 4000-   External housing 4010-   Upper portion 4012-   Lower portion 4014-   Panel 4015-   Chassis 4016-   Handle 4018-   Pneumatic block 4020-   Inlet air filter 4112-   Inlet muffler 4122-   Outlet muffler 4124-   Blower 4142-   Air circuit 4170-   Electrical components 4200-   Printed Circuit Board Assembly (PCBA) 4202-   Power supply 4210-   Input device 4220-   Pressure sensor 4272-   Flow rate sensor 4274-   Algorithms 4300-   Humidifier 5000-   Seal-forming structure 5100-   Cushion assembly 5105-   Support structure 5120-   Sealing portion 5130-   Patient interface 6000-   Seal-forming structure 6100-   Cushion assembly 6105-   Support structure 6120-   Sealing portion 6130-   Positioning and stabilizing structure 6300-   Left arm 6305-   Right arm 6307-   Joint 6312-   Air delivery tube 6348-   Tube 6350-   Inner layer 6352-   Outer layer 6354-   Textile sheet 6360-   membrane 6362-   Tube sheet 6364-   Outer covering 6366-   membrane 6368-   membrane 6370-   Air passage 6372-   Connection port 6600-   Seal-forming structure 7100-   Cushion assembly 7105-   Support structure 7120-   Sealing portion 7130-   Seal-forming structure 8100-   Cushion assembly 8105-   Support structure 8120-   End portion 8122-   Sealing portion 8130-   Sealing portion 8130-   Patient interface 9000-   Seal-forming structure 9100-   Cushion assembly 9105-   Support structure 9120-   Connector 9122-   Sealing portion 9130-   Frame 9200-   Headgear attachment portions 9210-   Positioning and stabilising structure 9300-   Rear strap 9310-   Crown strap 9312-   Cavity 10001-   Support structure 10120-   Underlying cushion 10121-   Attachment portion 10122-   Sealing lip 10124-   Clip 10126-   Sealing portion 10130-   Membrane layer 10131-   Sealing portion 10132-   Textile material 10133-   Support section 10135-   Seal biasing portion 10140-   Seal biasing portion 10140′-   Inwardly curved end portion 10142-   Air-assisted support region 10144-   Adhesive 10150-   Plenum chamber 10200-   Connector 10210-   Underlying cushion 11121-   Plenum chamber 11200-   Support structure 12120-   Underlying cushion 12121-   Plenum chamber 13200-   Patient interface 14000-   Cavity 14001-   Seal-forming structure 14100-   Nasal portion 14101-   Oral portion 14102-   Nasal portion holes 14103-   Oral portion hole 14104-   Cushion assembly 14105-   Bridge portion 14106-   Support structure 14120-   Underlying cushion 14121-   Underlying cushion 14122-   Sealing portion 14130-   Plenum chamber 14200-   Positioning and stabilising structure 14300-   Clip 14301-   Upper strap 14302-   Lower strap 14303-   Strap connector 14304-   Vent 14400-   Connection port 14600-   Conduit connector 14800-   Conduit connector housing 14801-   Conduit connection end 14802-   Conduit connector inlet hole 14803-   Conduit connector vent hole 14831-   Anti-asphyxia valve assembly 14850-   Conduit 14900-   Sleeve 14901-   Tie connector 14902-   Connection port housing 14903-   Support structure 15120-   Underlying cushion 15121-   Patient interface 16000-   Frame assembly 16100-   Opening 16105-   Shroud 16110-   Upper headgear connector arm 16134-   Central flexible portion 16140-   Peripheral flexible portion 16145-   Lower headgear connector arm 16154-   Magnetic connector 16155-   Headgear clip 16160-   Cushion assembly 16175-   Shell 16180-   Seal-forming structure 16200-   Support structure 16220-   Underlying cushion 16221-   Sealing portion 16230-   Opening 16305-   Flange 16310-   Cavity 16500-   Elbow assembly 16600-   First end portion 16610-   Second end portion 16620-   Swivel connector 16625-   Channel 16645-   Pinch arm 16650-   Vent holes 16700-   Arm cover 16750-   Headgear 16800-   Upper side strap 16802-   Lower side strap 16804-   Crown strap 16806-   Support structure 17120-   Underlying cushion 17121-   First portion 17123-   Reinforcing member 17125-   Support structure 18120-   Underlying cushion 18121-   Clip 18126-   Support structure 19120-   Underlying cushion 19121-   First portion 19123-   Support structure 20120-   Underlying cushion 20121-   First portion 20123-   Support structure 21120-   Underlying cushion 21121-   First portion 21123-   Support structure 22120-   Underlying cushion 22121-   First portion 22123-   Support structure 23120-   Underlying cushion 23121-   Clip 23126-   Support structure 24120-   Underlying cushion 24121-   Inner layer 24124-   Clip 24126-   Support structure 26120-   Sealing portion modular assembly 26400-   Supporting frame 26450-   Modular supporting structure 26480-   First mold 26500-   Second mold 26550-   Cushion assembly 27105-   Upper supporting frame portion 27202-   Lower supporting frame portion 27204-   Elastic region 27108-   Cushion assembly 28105-   Supporting frame 28200-   Seal-forming structure 29100-   Cushion assembly 29105-   Support structure 29120-   Sealing portion 29130-   Grip pad 29150-   Patient interface 30000-   Cavity 30001-   Seal-forming structure 30100-   Nasal portion 30101-   Oral portion 30102-   Nasal portion holes 30103-   Oral portion hole 30104-   Cushion assembly 30105-   Support structure 30120-   Sealing portion 30130-   Plenum chamber or shell 30200-   Inlet port 30240-   Positioning and stabilising structure 30300-   Upper straps 30310-   Upper strap connection points 30315-   Lower straps 30320-   Lower strap connection point 30325-   Lower strap clip 30326-   Top crown strap 30330-   Lateral crown straps 30332-   Neck strap 30334-   Frame 30350-   Frame inlet connection port 30354-   Connection rim 30355-   Vent 30400-   Swivel elbow assembly 30610-   Connection port 30600-   Cavity 31001-   Seal-forming structure 31100-   Nasal portion 31101-   Oral portion 31102-   Nasal portion holes 31103-   Oral portion hole 31104-   Cushion assembly 31105-   Support structure 31120-   Sealing portion 31130-   Grip pad 31150-   Plenum chamber 31200-   Plenum chamber holes 31210-   Vent 31400-   Seal-forming structure 32100-   Support structure 32120-   Marginal edge 32122-   Marginal edge 32125-   Sealing portion 32130-   Stem 32135-   Lateral region 32136-   Central region 32138-   Active region 32140-   Non-active region 32142-   Seal biasing portion 32160-   Folds, pleats, or undulations 32162-   Step 32164-   Channel 32165-   Wing 32166-   Protrusion 32167-   Inlet port 32170-   Connector gusset 32172

1. A patient interface for sealed delivery of a flow of air at acontinuously positive pressure with respect to ambient air pressure toan entrance to a patient's airways including at least entrance of apatient's nares, wherein the patient interface is configured to maintaina therapy pressure in a range of about 4 cmH2O to about 30 cmH2O aboveambient air pressure in use, throughout a patient's respiratory cycle,while the patient is sleeping, to ameliorate sleep disordered breathing;said patient interface comprising: a cushion assembly including: aplenum chamber at least partially forming a cavity pressurisable to atherapeutic pressure of at least 6 cmH₂O above ambient air pressure,said plenum chamber including a plenum chamber inlet port sized andstructured to receive a flow of air at the therapeutic pressure forbreathing by a patient; and a seal-forming structure having a textilemembrane constructed and arranged to form a pressure-assisted seal witha region of the patient's face surrounding an entrance to the patient'sairways inferior to a nasal bridge region of the patient's face, saidtextile membrane having a hole formed therein such that the flow of airat said therapeutic pressure is delivered to at least an entrance to thepatient's nares, the seal-forming structure constructed and arranged tomaintain said therapeutic pressure in the cavity throughout thepatient's respiratory cycle in use, wherein the seal-forming structureincludes a flexible support structure to hold the textile membrane in apredefined curved shape, the textile membrane being configured to sealwith an underside of the patient's nose including the patient'ssubnasale and the patient's pronasale, wherein the seal-formingstructure includes a seal biasing portion extending along a perimeter ofthe cushion assembly at least in lateral regions of the cushionassembly, the seal biasing portion being formed of a material that isdifferent than a material of the textile membrane, the seal biasingportion being less rigid than adjacent portions of the support structuresuch that the seal biasing portion is configured to inflate uponpressurization of the cavity in use thereby allowing the seal biasingportion to extend a reach of the textile membrane and decouple thetextile membrane from external forces applied to the plenum chamber whenactivated in use, and wherein the seal biasing portion is configured toextend the reach of the textile membrane a greater distance in thelateral regions of the cushion assembly than in at least a portion of acentral region of the cushion assembly such that when the seal biasingportion is activated in use the central region forms a bending orflexing area thereby allowing the textile membrane in the lateralregions to cradle or pinch the patient's nasal alar.
 2. The patientinterface of claim 1, wherein the textile membrane in the lateralregions is configured to extend in a posterosuperior direction and aleft-right direction to facilitate cradling or pinching the patient'snasal alar when the seal biasing portion is activated in use.
 3. Thepatient interface of claim 1, wherein, in use, the textile membrane isconfigured to press against the patient's face such that the patient'snose is not received in the cavity.
 4. The patient interface of claim 1,wherein the seal biasing portion is omitted in at least a portion of thecentral portion of the cushion assembly.
 5. The patient interface ofclaim 1, wherein the seal biasing portion extends around an entireperimeter of the cushion assembly.
 6. The patient interface of claim 1,wherein a size of the seal biasing portion varies around the perimeterof the cushion assembly.
 7. The patient interface of claim 1, whereinthe seal biasing portion is larger in the lateral regions and smaller inthe central region of the cushion assembly.
 8. The patient interface ofclaim 1, wherein the size of the seal biasing portion tapers from alarger seal biasing portion in the lateral regions to a smaller sealbiasing portion toward the central region of the cushion assembly. 9.The patient interface of claim 1, wherein the seal biasing portioncomprises an indented channel or recess.
 10. The patient interface ofclaim 1, wherein the seal biasing portion comprises an externalprotrusion.
 11. The patient interface of claim 1, wherein the sealbiasing portion comprises at least one fold, pleat, or undulation. 12.The patient interface of claim 11, wherein the at least one fold, pleat,or undulation allows the textile membrane to telescope towards thepatient's face in use when the seal biasing portion is activated. 13.The patient interface of claim 11, wherein the seal biasing portioncomprises a plurality of folds, pleats or undulations.
 14. The patientinterface of claim 13, wherein the plurality of folds, pleats orundulations form a sinusoidal wave in cross section.
 15. The patientinterface of claim 1, wherein the seal biasing portion comprises a stepand a wing, the step and wing being angled with respect to one another.16. The patient interface of claim 1, wherein the seal biasing portionis disposed between the support structure and the textile membrane. 17.The patient interface of claim 1, wherein the seal biasing portion isdisposed between the plenum chamber and the support structure.
 18. Thepatient interface of claim 1, wherein the cushion assembly includes astem that projects from the plenum chamber to support the seal-formingstructure.
 19. The patient interface of claim 1, wherein the sealbiasing portion extends through the lateral regions of the cushionassembly at an angle α with respect to a plane extending along ananterior side of the cushion assembly.
 20. The patient interface ofclaim 19, wherein the angle α is between 30°-60°.
 21. The patientinterface of claim 1, wherein the seal-forming structure is arrangedsuch that the textile membrane has a saddle shape configured toaccommodate the underside of the patient's nose in use.
 22. The patientinterface of claim 1, wherein the support structure and the seal biasingportion comprise silicone.
 23. The patient interface of claim 1, whereinthe textile membrane is attached to the support structure along an outerperimeter of the textile membrane such that the textile membrane extendsradially inwardly beyond the support structure.
 24. The patientinterface of claim 1, wherein the support structure comprises siliconeand the textile membrane is molded to an inner edge of the supportstructure.
 25. The patient interface of claim 1, wherein the at leastone hole in the textile membrane comprises two holes, and a bridgeportion is disposed between the two holes in the textile membrane. 26.The patient interface of claim 1, wherein the textile membrane comprisesa membrane layer applied to a textile material to make the textilematerial substantially air impermeable.
 27. The patient interface ofclaim 1, wherein the plenum chamber comprises silicone and is formed inone piece with the support structure.
 28. The patient interface of claim1, further comprising a positioning and stabilising structure to providea force to hold the seal-forming structure in a therapeuticallyeffective position on the patient's head, the positioning andstabilising structure comprising a tie, the tie being constructed andarranged so that at least a portion overlies a region of the patient'shead superior to an otobasion superior of the patient's head in use. 29.The patient interface of claim 1, further comprising a vent structure toallow a continuous flow of gases exhaled by the patient from an interiorof the cavity to ambient, said vent structure being sized and shaped tomaintain the therapeutic pressure in the cavity in use.
 30. The patientinterface of claim 1, wherein the plenum chamber and seal-formingstructure form a nasal cushion.
 31. A treatment system used fortreatment of sleep disordered breathing, comprising: the patientinterface according to claim 1; a respiratory pressure therapy (RPT)device to supply breathable gas at positive pressure; and an airdelivery tube to pass the breathable gas from the RPT device to thepatient interface.
 32. A patient interface for sealed delivery of a flowof air at a continuously positive pressure with respect to ambient airpressure to an entrance to a patient's airways including at leastentrance of a patient's nares, wherein the patient interface isconfigured to maintain a therapy pressure in a range of about 4 cmH2O toabout 30 cmH2O above ambient air pressure in use, throughout a patient'srespiratory cycle, while the patient is sleeping, to ameliorate sleepdisordered breathing; said patient interface comprising: a cushionassembly including: a plenum chamber at least partially forming a cavitypressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, said plenum chamber including a plenum chamberinlet port sized and structured to receive a flow of air at thetherapeutic pressure for breathing by a patient; and a seal-formingstructure having a sealing portion constructed and arranged to form apressure-assisted seal with a region of the patient's face surroundingan entrance to the patient's airways inferior to a nasal bridge regionof the patient's face, said sealing portion having a hole formed thereinsuch that the flow of air at said therapeutic pressure is delivered toat least an entrance to the patient's nares, the seal-forming structureconstructed and arranged to maintain said therapeutic pressure in thecavity throughout the patient's respiratory cycle in use, wherein theseal-forming structure includes a flexible support structure to supportthe sealing portion, the sealing portion being configured to seal withan underside of the patient's nose including the patient's subnasale andthe patient's pronasale, wherein the seal-forming structure includes aseal biasing portion disposed with the sealing portion along a posteriorpatient-facing surface of the cushion assembly, the seal biasing portionincluding at least one of fold, pleat or undulation extending betweenthe sealing portion and the support structure, wherein, prior topressurization of the cavity during use, the sealing portion liessubstantially flush with a posterior-most portion of the seal biasingportion, and wherein the seal biasing portion is configured to inflateupon pressurization of the cavity in use thereby causing the sealingportion to extend or telescope beyond other portions of the posteriorpatient-facing surface of the cushion assembly in a direction towards atleast a portion of the patient's face.
 33. The patient interface ofclaim 32, wherein the seal biasing portion comprises a plurality offolds, pleats or undulations that form a sinusoidal wave in crosssection.
 34. The patient interface of claim 32, wherein the seal biasingportion is disposed at least in lateral regions of the cushion assembly.35. The patient interface of claim 34, wherein the sealing portion isconfigured to extend or telescope a greater distance in the lateralregions of the cushion assembly than in a central region of the cushionassembly such that when the seal biasing portion is activated in use thecentral region forms a bending or flexing area thereby allowing thesealing portion in the lateral regions to cradle or pinch the patient'snasal alar.
 36. The patient interface of claim 32, wherein a size of theseal biasing portion varies around the perimeter of the cushionassembly.
 37. The patient interface of claim 32, wherein the sealbiasing portion is larger in the lateral regions and smaller in thecentral region of the cushion assembly.
 38. The patient interface ofclaim 32, wherein the seal biasing portion extends around an entireperimeter of the cushion assembly.
 39. The patient interface of claim32, wherein the seal biasing portion is omitted in at least a portion ofthe central portion of the cushion assembly.
 40. The patient interfaceof claim 32, wherein the support structure and the seal biasing portioncomprise silicone.
 41. The patient interface of claim 32, wherein thesealing portion comprises a textile membrane. 42-46. (canceled)